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1.1       deraadt     1: <!DOCTYPE HTML PUBLIC  "-//IETF//DTD HTML Strict//EN">
                      2: <html>
                      3: <head>
1.20      deraadt     4: <title>OpenBSD Security</title>
1.1       deraadt     5: <link rev=made href=mailto:www@openbsd.org>
                      6: <meta name="resource-type" content="document">
                      7: <meta name="description" content="OpenBSD advisories">
                      8: <meta name="keywords" content="openbsd,main">
                      9: <meta name="distribution" content="global">
1.193     horacio    10: <meta name="copyright" content="This document copyright 1997-2002 by OpenBSD.">
1.1       deraadt    11: </head>
                     12:
                     13: <BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#23238E">
1.77      deraadt    14: <img alt="[OpenBSD]" height=30 width=141 SRC="images/smalltitle.gif">
1.106     deraadt    15: <p>
1.110     deraadt    16: <h2><font color=#e00000>Security</font><hr></h2>
1.1       deraadt    17:
1.114     philen     18: <table width="100%">
                     19: <tr>
                     20: <td colspan="2">
                     21: <strong>Index</strong>
                     22: </td>
                     23: </tr>
                     24: <tr>
                     25: <td valign="top">
1.106     deraadt    26: <a href=#goals>Security goals of the Project</a>.<br>
                     27: <a href=#disclosure>Full Disclosure policy</a>.<br>
                     28: <a href=#process>Source code auditing process</a>.<br>
1.111     aaron      29: <a href=#default>"Secure by Default"</a>.<br>
1.106     deraadt    30: <a href=#crypto>Use of Cryptography</a>.<br>
                     31: <p>
                     32: <a href=#watching>Watching changes</a>.<br>
                     33: <a href=#reporting>Reporting security issues</a>.<br>
1.107     deraadt    34: <a href=#papers>Further Reading</a><br>
1.106     deraadt    35: <p>
1.114     philen     36: </td>
                     37: <td valign="top">
1.187     deraadt    38: <a href="#30">For 3.0 security advisories</a>.<br>
1.173     deraadt    39: <a href="#29">For 2.9 security advisories</a>.<br>
1.152     deraadt    40: <a href="#28">For 2.8 security advisories</a>.<br>
1.124     deraadt    41: <a href="#27">For 2.7 security advisories</a>.<br>
1.119     deraadt    42: <a href="#26">For 2.6 security advisories</a>.<br>
1.114     philen     43: <a href="#25">For 2.5 security advisories</a>.<br>
                     44: <a href="#24">For 2.4 security advisories</a>.<br>
                     45: <a href="#23">For 2.3 security advisories</a>.<br>
                     46: <a href="#22">For 2.2 security advisories</a>.<br>
                     47: <a href="#21">For 2.1 security advisories</a>.<br>
                     48: <a href="#20">For 2.0 security advisories</a>.<br>
                     49: </td>
                     50: </tr>
                     51: </table>
1.56      deraadt    52: <hr>
                     53:
1.106     deraadt    54: <dl>
                     55: <a name=goals></a>
1.110     deraadt    56: <li><h3><font color=#e00000>Goal</font></h3><p>
1.22      deraadt    57:
1.14      deraadt    58: OpenBSD believes in strong security.  Our aspiration is to be NUMBER
1.22      deraadt    59: ONE in the industry for security (if we are not already there).  Our
                     60: open software development model permits us to take a more
                     61: uncompromising view towards increased security than Sun, SGI, IBM, HP,
                     62: or other vendors are able to.  We can make changes the vendors would
1.27      deraadt    63: not make.  Also, since OpenBSD is exported with <a href=crypto.html>
1.45      deraadt    64: cryptography</a>, we are able to take cryptographic approaches towards
                     65: fixing security problems.<p>
1.18      deraadt    66:
1.106     deraadt    67: <a name=disclosure></a>
1.110     deraadt    68: <li><h3><font color=#e00000>Full Disclosure</font></h3><p>
1.106     deraadt    69:
1.45      deraadt    70: Like many readers of the
1.102     deraadt    71: <a href=http://www.securityfocus.com/bugtraq/archive>
1.18      deraadt    72: BUGTRAQ mailing list</a>,
1.106     deraadt    73: we believe in full disclosure of security problems.  In the
                     74: operating system arena, we were probably the first to embrace
                     75: the concept.  Many vendors, even of free software, still try
                     76: to hide issues from their users.<p>
                     77:
                     78: Security information moves very fast in cracker circles.  On the other
                     79: hand, our experience is that coding and releasing of proper security
                     80: fixes typically requires about an hour of work -- very fast fix
                     81: turnaround is possible.  Thus we think that full disclosure helps the
                     82: people who really care about security.<p>
                     83:
1.153     jufi       84: <a name=process></a>
1.110     deraadt    85: <li><h3><font color=#e00000>Audit Process</font></h3><p>
1.15      deraadt    86:
1.12      deraadt    87: Our security auditing team typically has between six and twelve
1.45      deraadt    88: members who continue to search for and fix new security holes.  We
                     89: have been auditing since the summer of 1996.  The process we follow to
                     90: increase security is simply a comprehensive file-by-file analysis of
1.106     deraadt    91: every critical software component.  We are not so much looking for
                     92: security holes, as we are looking for basic software bugs, and if
1.138     deraadt    93: years later someone discovers the problem used to be a security
1.106     deraadt    94: issue, and we fixed it because it was just a bug, well, all the
                     95: better.  Flaws have been found in just about every area of the system.
                     96: Entire new classes of security problems have been found during our
                     97: audit, and often source code which had been audited earlier needs
                     98: re-auditing with these new flaws in mind.  Code often gets audited
                     99: multiple times, and by multiple people with different auditing
                    100: skills.<p>
1.12      deraadt   101:
1.94      deraadt   102: Some members of our security auditing team worked for Secure Networks,
                    103: the company that made the industry's premier network security scanning
                    104: software package Ballista (Secure Networks got purchased by Network
                    105: Associates, Ballista got renamed to Cybercop Scanner, and well...)
                    106: That company did a lot of security research, and thus fit in well
1.106     deraadt   107: with the OpenBSD stance.  OpenBSD passed Ballista's tests with flying
                    108: colours since day 1.<p>
1.31      deraadt   109:
1.34      deraadt   110: Another facet of our security auditing process is its proactiveness.
1.45      deraadt   111: In most cases we have found that the determination of exploitability
                    112: is not an issue.  During our ongoing auditing process we find many
                    113: bugs, and endeavor to fix them even though exploitability is not
                    114: proven.  We fix the bug, and we move on to find other bugs to fix.  We
                    115: have fixed many simple and obvious careless programming errors in code
                    116: and only months later discovered that the problems were in fact
                    117: exploitable.  (Or, more likely someone on
1.102     deraadt   118: <a href=http://www.securityfocus.com/bugtraq/archive>BUGTRAQ</a>
1.45      deraadt   119: would report that other operating systems were vulnerable to a `newly
                    120: discovered problem', and then it would be discovered that OpenBSD had
                    121: been fixed in a previous release).  In other cases we have been saved
                    122: from full exploitability of complex step-by-step attacks because we
                    123: had fixed one of the intermediate steps.  An example of where we
1.94      deraadt   124: managed such a success is the lpd advisory that Secure Networks put out.
                    125: <p>
1.29      deraadt   126:
1.110     deraadt   127: <li><h3><font color=#e00000>The Reward</font></h3><p>
1.106     deraadt   128:
1.45      deraadt   129: Our proactive auditing process has really paid off.  Statements like
1.35      deraadt   130: ``This problem was fixed in OpenBSD about 6 months ago'' have become
1.45      deraadt   131: commonplace in security forums like
1.102     deraadt   132: <a href=http://www.securityfocus.com/bugtraq/archive>BUGTRAQ</a>.<p>
1.35      deraadt   133:
1.45      deraadt   134: The most intense part of our security auditing happened immediately
1.80      espie     135: before the OpenBSD 2.0 release and during the 2.0-&gt;2.1 transition,
1.45      deraadt   136: over the last third of 1996 and first half of 1997.  Thousands (yes,
                    137: thousands) of security issues were fixed rapidly over this year-long
                    138: period; bugs like the standard buffer overflows, protocol
                    139: implementation weaknesses, information gathering, and filesystem
                    140: races.  Hence most of the security problems that we encountered were
                    141: fixed before our 2.1 release, and then a far smaller number needed
                    142: fixing for our 2.2 release.  We do not find as many problems anymore,
                    143: it is simply a case of diminishing returns.  Recently the security
                    144: problems we find and fix tend to be significantly more obscure or
                    145: complicated.  Still we will persist for a number of reasons:<p>
1.36      deraadt   146:
1.35      deraadt   147: <ul>
1.45      deraadt   148: <li>Occasionally we find a simple problem we missed earlier. Doh!
1.35      deraadt   149: <li>Security is like an arms race; the best attackers will continue
1.45      deraadt   150:        to search for more complicated exploits, so we will too.
                    151: <li>Finding and fixing subtle flaws in complicated software is
                    152:        a lot of fun.
1.35      deraadt   153: </ul>
1.106     deraadt   154: <p>
1.15      deraadt   155:
1.14      deraadt   156: The auditing process is not over yet, and as you can see we continue
1.28      deraadt   157: to find and fix new security flaws.<p>
1.12      deraadt   158:
1.106     deraadt   159: <a name=default></a>
1.110     deraadt   160: <li><h3><font color=#e00000>"Secure by Default"</font></h3><p>
1.106     deraadt   161:
                    162: To ensure that novice users of OpenBSD do not need to become security
                    163: experts overnight (a viewpoint which other vendors seem to have), we
                    164: ship the operating system in a Secure by Default mode.  All non-essential
                    165: services are disabled.  As the user/administrator becomes more familiar
                    166: with the system, he will discover that he has to enable daemons and other
                    167: parts of the system.  During the process of learning how to enable a new
                    168: service, the novice is more likely to learn of security considerations.<p>
                    169:
                    170: This is in stark contrast to the increasing number of systems that
                    171: ship with NFS, mountd, web servers, and various other services enabled
                    172: by default, creating instantaneous security problems for their users
                    173: within minutes after their first install.<p>
                    174:
1.153     jufi      175: <a name=crypto></a>
1.110     deraadt   176: <li><h3><font color=#e00000>Cryptography</font></h3><p>
1.106     deraadt   177:
                    178: And of course, since the OpenBSD project is based in Canada, it is possible
                    179: for us to integrate cryptography.  For more information, read the page
1.116     deraadt   180: outlining <a href=crypto.html>what we have done with cryptography</a>.</p>
1.106     deraadt   181:
1.110     deraadt   182: <li><h3><font color=#e00000>Advisories</font></h3><p>
1.106     deraadt   183:
                    184: <dl>
                    185:
                    186: <li>
1.187     deraadt   187: <a name=30></a>
                    188:
                    189: <h3><font color=#e00000>OpenBSD 3.0 Security Advisories</font></h3>
                    190: These are the OpenBSD 3.0 advisories -- all these problems are solved
                    191: in <a href=anoncvs.html>OpenBSD current</a> and the
                    192: <a href=stable.html>patch branch</a>.
                    193:
                    194: <p>
                    195: <ul>
1.194   ! mpech     196: <li><a href=errata.html#syspipe>February 4, 2002:
        !           197:        The wrong filedescriptors are released when pipe(2) failed.</a>
1.192     jason     198: <li><a href=errata.html#ptrace>January 21, 2002:
                    199:        A race condition between the ptrace(2) and execve(2) system calls
                    200:        allows an attacker to modify the memory contents of suid/sgid
                    201:        processes which could lead to compromise of the super-user account.</a>
1.191     millert   202: <li><a href=errata.html#sudo>January 17, 2002:
                    203:        There is a security hole in sudo(8) that can be exploited
                    204:        when the Postfix sendmail replacement is installed that may
                    205:        allow an attacker on the local host to gain root privileges.</a>
1.189     millert   206: <li><a href=errata.html#lpd>November 28, 2001:
                    207:        An attacker can trick a machine running the lpd daemon into
                    208:        creating new files in the root directory from a machine with
                    209:        remote line printer access.</a>
1.188     millert   210: <li><a href=errata.html#vi.recover>November 13, 2001:
                    211:        The vi.recover script can be abused in such a way as
                    212:        to cause arbitrary zero-length files to be removed.</a>
1.190     mpech     213: <li><a href=errata.html#pf>November 13, 2001:
                    214:        pf(4) was incapable of dealing with certain ipv6 icmp packets,
                    215:        resulting in a crash.</a>
                    216: <li><a href=errata.html#sshd>November 12, 2001:
                    217:        A security hole that may allow an attacker to partially authenticate
                    218:        if -- and only if -- the administrator has enabled KerberosV.</a>
1.187     deraadt   219: </ul>
                    220:
                    221: <p>
                    222: <li>
1.173     deraadt   223: <a name=29></a>
                    224:
                    225: <h3><font color=#e00000>OpenBSD 2.9 Security Advisories</font></h3>
                    226: These are the OpenBSD 2.9 advisories -- all these problems are solved
                    227: in <a href=anoncvs.html>OpenBSD current</a> and the
1.179     jufi      228: <a href=stable.html>patch branch</a>.
1.173     deraadt   229:
                    230: <p>
                    231: <ul>
1.191     millert   232: <li><a href=errata29.html#sudo>January 17, 2002:
                    233:        There is a security hole in sudo(8) that can be exploited
                    234:        when the Postfix sendmail replacement is installed that may
                    235:        allow an attacker on the local host to gain root privileges.</a>
1.189     millert   236: <li><a href=errata29.html#lpd2>November 28, 2001:
                    237:        An attacker can trick a machine running the lpd daemon into
                    238:        creating new files in the root directory from a machine with
                    239:        remote line printer access.</a>
1.190     mpech     240: <li><a href=errata29.html#vi.recover>November 13, 2001:
                    241:        The vi.recover script can be abused in such a way as
                    242:        to cause arbitrary zero-length files to be removed.</a>
1.185     deraadt   243: <li><a href=errata29.html#uucp>September 11, 2001:
1.184     millert   244:        A security hole exists in uuxqt(8) that may allow an
                    245:        attacker to gain root privileges.</a>
1.185     deraadt   246: <li><a href=errata29.html#lpd>August 29, 2001:
1.183     millert   247:        A security hole exists in lpd(8) that may allow an
                    248:        attacker to gain root privileges if lpd is running.</a>
1.185     deraadt   249: <li><a href=errata29.html#sendmail2>August 21, 2001:
1.181     millert   250:        A security hole exists in sendmail(8) that may allow an
                    251:        attacker on the local host to gain root privileges.</a>
1.185     deraadt   252: <li><a href=errata29.html#nfs>July 30, 2001:
1.180     jason     253:        A kernel buffer overflow in the NFS code can be used to execute
                    254:        arbitrary code by users with mount privileges (only root by
1.181     millert   255:        default).</a>
1.185     deraadt   256: <li><a href=errata29.html#kernexec>June 15, 2001:
1.178     aaron     257:        A race condition in the kernel can lead to local root compromise.</a>
1.185     deraadt   258: <li><a href=errata29.html#sshcookie>June 12, 2001:
1.177     markus    259:         sshd(8) allows users to delete arbitrary files named "cookies"
                    260:         if X11 forwarding is enabled. X11 forwarding is disabled
                    261:         by default.</a>
1.185     deraadt   262: <li><a href=errata29.html#fts>May 30, 2001:
1.176     millert   263:         Programs using the fts routines can be tricked into changing
                    264:         into the wrong directory.</a>
1.185     deraadt   265: <li><a href=errata29.html#sendmail>May 29, 2001:
1.174     millert   266:        Sendmail signal handlers contain unsafe code,
                    267:        leading to numerous race conditions.</a>
1.173     deraadt   268: </ul>
                    269:
                    270: <p>
                    271: <li>
1.152     deraadt   272: <a name=28></a>
                    273:
                    274: <h3><font color=#e00000>OpenBSD 2.8 Security Advisories</font></h3>
                    275: These are the OpenBSD 2.8 advisories -- all these problems are solved
1.154     millert   276: in <a href=anoncvs.html>OpenBSD current</a> and the
1.179     jufi      277: <a href=stable.html>patch branch</a>.
1.152     deraadt   278:
                    279: <p>
                    280: <ul>
1.184     millert   281: <li><a href=errata28.html#uucp>September 11, 2001:
                    282:        A security hole exists in uuxqt(8) that may allow an
                    283:        attacker to gain root privileges.</a>
1.183     millert   284: <li><a href=errata28.html#lpd>August 29, 2001:
                    285:        A security hole exists in lpd(8) that may allow an
                    286:        attacker to gain root privileges if lpd is running.</a>
1.181     millert   287: <li><a href=errata28.html#sendmail2>August 21, 2001:
                    288:        A security hole exists in sendmail(8) that may allow an
                    289:        attacker on the local host to gain root privileges.</a>
1.178     aaron     290: <li><a href=errata28.html#kernexec>June 15, 2001:
                    291:        A race condition in the kernel can lead to local root compromise.</a>
1.176     millert   292: <li><a href=errata28.html#fts>May 30, 2001:
                    293:         Programs using the fts routines can be tricked into changing
                    294:         into the wrong directory.</a>
1.175     millert   295: <li><a href=errata28.html#sendmail>May 29, 2001:
                    296:        Sendmail signal handlers contain unsafe code,
                    297:        leading to numerous race conditions.</a>
1.173     deraadt   298: <li><a href=errata28.html#ipf_frag>Apr 23, 2001:
1.172     ericj     299:        IPF contains a serious bug with its handling of fragment cacheing.</a>
1.173     deraadt   300: <li><a href=errata28.html#glob_limit>Apr 23, 2001:
1.172     ericj     301:        ftpd(8) contains a potential DoS relating to glob(3).</a>
1.173     deraadt   302: <li><a href=errata28.html#glob>Apr 10, 2001:
1.170     ericj     303:        The glob(3) library call contains multiple buffer overflows.</a>
1.173     deraadt   304: <li><a href=errata28.html#readline>Mar 18, 2001:
1.169     millert   305:        The readline library creates history files with permissive modes based on the user's umask.</a>
1.173     deraadt   306: <li><a href=errata28.html#ipsec_ah>Mar 2, 2001:
1.167     ericj     307:        Insufficient checks in the IPSEC AH IPv4 option handling code can lead to a buffer overrun in the kernel.</a>
1.173     deraadt   308: <li><a href=errata28.html#userldt>Mar 2, 2001:
1.168     horacio   309:        The <b>USER_LDT</b> kernel option allows an attacker to gain access to privileged areas of kernel memory.</a>
1.173     deraadt   310: <li><a href=errata28.html#sudo>Feb 22, 2001:
1.171     millert   311:        a non-exploitable buffer overflow was fixed in sudo(8).</a>
1.173     deraadt   312: <li><a href=errata28.html#named>Jan 29, 2001:
1.163     jason     313:        merge named(8) with ISC BIND 4.9.8-REL, which fixes some buffer vulnerabilities.</a>
1.173     deraadt   314: <li><a href=errata28.html#rnd>Jan 22, 2001:
1.162     jason     315:        rnd(4) did not use all of its input when written to.</a>
1.173     deraadt   316: <li><a href=errata28.html#xlock>Dec 22, 2000:
1.159     ericj     317:        xlock(1)'s authentication was re-done to authenticate via a named pipe. (patch and new xlock binaries included).</a>
1.173     deraadt   318: <li><a href=errata28.html#procfs>Dec 18, 2000:
1.157     ericj     319:        Procfs contains numerous overflows. Procfs is not used by default in OpenBSD. (patch included).</a>
1.173     deraadt   320: <li><a href=errata28.html#kerberos2>Dec 10, 2000:
1.156     deraadt   321:        Another problem exists in KerberosIV libraries (patch included).</a>
1.173     deraadt   322: <li><a href=errata28.html#kerberos>Dec 7, 2000:
1.155     deraadt   323:        A set of problems in KerberosIV exist (patch included).</a>
1.173     deraadt   324: <li><a href=errata28.html#ftpd>Dec 4, 2000:
1.154     millert   325:        A single-byte buffer overflow exists in ftpd (patch included).</a>
1.152     deraadt   326: </ul>
                    327:
                    328: <p>
                    329: <li>
1.124     deraadt   330: <a name=27></a>
                    331:
                    332: <h3><font color=#e00000>OpenBSD 2.7 Security Advisories</font></h3>
                    333: These are the OpenBSD 2.7 advisories -- all these problems are solved
                    334: in <a href=anoncvs.html>OpenBSD current</a>.  Obviously, all the
                    335: OpenBSD 2.6 advisories listed below are fixed in OpenBSD 2.7.
                    336:
                    337: <p>
                    338: <ul>
1.169     millert   339: <li><a href=errata27.html#readline>Mar 18, 2001:
                    340:        The readline library creates history files with permissive modes based on the user's umask.</a>
                    341: <li><a href=errata27.html#sudo>Feb 22, 2001:
                    342:        a buffer overflow was fixed in sudo(8).</a>
1.154     millert   343: <li><a href=errata27.html#ftpd>Dec 4, 2000:
                    344:        A single-byte buffer overflow exists in ftpd (patch included).</a>
1.152     deraadt   345: <li><a href=errata27.html#sshforwarding>Nov 10, 2000:
                    346:        Hostile servers can force OpenSSH clients to do agent or X11 forwarding.
                    347:        (patch included)</a>
                    348: <li><a href=errata27.html#xtrans>Oct 26, 2000:
1.151     matthieu  349:        X11 libraries have 2 potential overflows in xtrans code.
                    350:        (patch included)</a>
1.152     deraadt   351: <li><a href=errata27.html#httpd>Oct 18, 2000:
1.150     beck      352:        Apache mod_rewrite and mod_vhost_alias modules could expose files
                    353:        on the server in certain configurations if used.
                    354:        (patch included)</a>
1.164     deraadt   355: <li><a href=errata27.html#telnetd>Oct 10, 2000:
1.149     millert   356:        The telnet daemon does not strip out the TERMINFO, TERMINFO_DIRS,
                    357:        TERMPATH and TERMCAP environment variables as it should.
                    358:        (patch included)</a>
1.152     deraadt   359: <li><a href=errata27.html#format_strings>Oct 6, 2000:
1.148     millert   360:        There are printf-style format string bugs in several privileged
                    361:        programs.  (patch included)</a>
1.152     deraadt   362: <li><a href=errata27.html#curses>Oct 6, 2000:
1.147     millert   363:        libcurses honored terminal descriptions in the $HOME/.terminfo
                    364:        directory as well as in the TERMCAP environment variable for
                    365:        setuid and setgid applications.
1.146     deraadt   366:        (patch included)</a>
1.152     deraadt   367: <li><a href=errata27.html#talkd>Oct 6, 2000:
1.146     deraadt   368:        A format string vulnerability exists in talkd(8).
                    369:        (patch included)</a>
1.152     deraadt   370: <li><a href=errata27.html#pw_error>Oct 3, 2000:
1.145     aaron     371:        A format string vulnerability exists in the pw_error() function of the
                    372:        libutil library, yielding localhost root through chpass(1).
                    373:        (patch included)</a>
1.152     deraadt   374: <li><a href=errata27.html#ipsec>Sep 18, 2000:
1.144     jason     375:        Bad ESP/AH packets could cause a crash under certain conditions.
                    376:        (patch included)</a>
1.152     deraadt   377: <li><a href=errata27.html#xlock>Aug 16, 2000:
1.141     deraadt   378:        A format string vulnerability (localhost root) exists in xlock(1).
                    379:        (patch included)</a>
1.152     deraadt   380: <li><a href=errata27.html#X11_libs>July 14, 2000:
1.139     deraadt   381:        Various bugs found in X11 libraries have various side effects, almost
                    382:        completely denial of service in OpenBSD.
                    383:        (patch included)</a>
1.152     deraadt   384: <li><a href=errata27.html#ftpd>July 5, 2000:
1.136     deraadt   385:        Just like pretty much all the other unix ftp daemons
                    386:        on the planet, ftpd had a remote root hole in it.
                    387:        Luckily, ftpd was not enabled by default.
1.137     deraadt   388:        The problem exists if anonymous ftp is enabled.
1.136     deraadt   389:        (patch included)</a>
1.152     deraadt   390: <li><a href=errata27.html#mopd>July 5, 2000:
1.136     deraadt   391:        Mopd, very rarely used, contained some buffer overflows.
                    392:        (patch included)</a>
1.152     deraadt   393: <li><a href=errata27.html#libedit>June 28, 2000:
1.135     deraadt   394:        libedit would check for a <b>.editrc</b> file in the current
                    395:        directory.  Not known to be a real security issue, but a patch
                    396:        is available anyways.
                    397:        (patch included)</a>
1.152     deraadt   398: <li><a href=errata27.html#dhclient>June 24, 2000:
1.134     deraadt   399:        A serious bug in dhclient(8) could allow strings from a
                    400:        malicious dhcp server to be executed in the shell as root.
                    401:        (patch included)</a>
1.152     deraadt   402: <li><a href=errata27.html#isakmpd>June 9, 2000:
1.133     deraadt   403:        A serious bug in isakmpd(8) policy handling wherein
                    404:        policy verification could be completely bypassed in isakmpd.
                    405:        (patch included)</a>
1.152     deraadt   406: <li><a href=errata27.html#uselogin>June 6, 2000:
1.132     deraadt   407:        The non-default flag UseLogin in <b>/etc/sshd_config</b> is broken,
                    408:        should not be used, and results in security problems on
                    409:        other operating systems.</a>
1.152     deraadt   410: <li><a href=errata27.html#bridge>May 26, 2000:
1.129     deraadt   411:        The bridge(4) <i>learning</i> flag may be bypassed.
1.128     deraadt   412:        (patch included)</a>
1.152     deraadt   413: <li><a href=errata27.html#ipf>May 25, 2000:
1.127     kjell     414:        Improper use of ipf <i>keep-state</i> rules can result
                    415:        in firewall rules being bypassed. (patch included)</a>
                    416:
1.124     deraadt   417: </ul>
                    418:
                    419: <p>
                    420: <li>
1.119     deraadt   421: <a name=26></a>
                    422:
                    423: <h3><font color=#e00000>OpenBSD 2.6 Security Advisories</font></h3>
                    424: These are the OpenBSD 2.6 advisories -- all these problems are solved
                    425: in <a href=anoncvs.html>OpenBSD current</a>.  Obviously, all the
                    426: OpenBSD 2.5 advisories listed below are fixed in OpenBSD 2.6.
                    427:
                    428: <p>
                    429: <ul>
1.130     deraadt   430: <li><a href=errata26.html#semconfig>May 26, 2000:
                    431:        SYSV semaphore support contained an undocumented system call
1.131     deraadt   432:        which could wedge semaphore-using processes from exiting. (patch included)</a>
1.127     kjell     433: <li><a href=errata26.html#ipf>May 25, 2000:
                    434:        Improper use of ipf <i>keep-state</i> rules can result
                    435:        in firewall rules being bypassed. (patch included)</a>
1.126     deraadt   436: <li><a href=errata26.html#xlockmore>May 25, 2000:
1.125     deraadt   437:        xlockmore has a bug which a localhost attacker can use to gain
                    438:        access to the encrypted root password hash (which is normally
                    439:        encoded using blowfish (see
                    440:        <a href="http://www.openbsd.org/cgi-bin/man.cgi?query=crypt&sektion=3">
                    441:        crypt(3)</a>)
                    442:        (patch included).</a>
1.126     deraadt   443: <li><a href=errata26.html#procfs>Jan 20, 2000:
1.123     deraadt   444:        Systems running with procfs enabled and mounted are
                    445:        vulnerable to a very tricky exploit.  procfs is not
                    446:        mounted by default.
                    447:        (patch included).</a>
1.190     mpech     448: <li><a href=errata26.html#sendmail>Dec 4, 1999:
                    449:        Sendmail permitted any user to cause a aliases file wrap,
                    450:        thus exposing the system to a race where the aliases file
                    451:        did not exist.
1.119     deraadt   452:        (patch included).</a>
1.190     mpech     453: <li><a href=errata26.html#poll>Dec 4, 1999:
                    454:        Various bugs in poll(2) may cause a kernel crash.</a>
1.126     deraadt   455: <li><a href=errata26.html#sslUSA>Dec 2, 1999:
1.120     deraadt   456:        A buffer overflow in the RSAREF code included in the
                    457:        USA version of libssl, is possibly exploitable in
                    458:        httpd, ssh, or isakmpd, if SSL/RSA features are enabled.
1.124     deraadt   459:        (patch included).<br></a>
                    460:        <strong>Update:</strong> Turns out that this was not exploitable
                    461:        in any of the software included in OpenBSD 2.6.
1.190     mpech     462: <li><a href=errata26.html#ifmedia>Nov 9, 1999:
                    463:        Any user could change interface media configurations, resulting in
                    464:        a localhost denial of service attack.
1.121     deraadt   465:        (patch included).</a>
1.119     deraadt   466: </ul>
                    467:
                    468: <p>
                    469: <li>
                    470:
1.93      deraadt   471: <a name=25></a>
1.106     deraadt   472:
1.110     deraadt   473: <h3><font color=#e00000>OpenBSD 2.5 Security Advisories</font></h3>
1.93      deraadt   474: These are the OpenBSD 2.5 advisories -- all these problems are solved
                    475: in <a href=anoncvs.html>OpenBSD current</a>.  Obviously, all the
                    476: OpenBSD 2.4 advisories listed below are fixed in OpenBSD 2.5.
                    477:
1.96      deraadt   478: <p>
1.104     deraadt   479: <ul>
1.117     deraadt   480: <li><a href=errata25.html#cron>Aug 30, 1999:
1.103     deraadt   481:        In cron(8), make sure argv[] is NULL terminated in the
                    482:        fake popen() and run sendmail as the user, not as root.
                    483:        (patch included).</a>
1.117     deraadt   484: <li><a href=errata25.html#miscfs>Aug 12, 1999: The procfs and fdescfs
1.101     deraadt   485:        filesystems had an overrun in their handling of uio_offset
                    486:        in their readdir() routines. (These filesystems are not
                    487:        enabled by default). (patch included).</a>
1.117     deraadt   488: <li><a href=errata25.html#profil>Aug 9, 1999: Stop profiling (see profil(2))
1.100     deraadt   489:        when we execve() a new process. (patch included).</a>
1.117     deraadt   490: <li><a href=errata25.html#ipsec_in_use>Aug 6, 1999: Packets that should have
1.98      deraadt   491:        been handled by IPsec may be transmitted as cleartext.
                    492:        PF_KEY SA expirations may leak kernel resources.
                    493:        (patch included).</a>
1.117     deraadt   494: <li><a href=errata25.html#rc>Aug 5, 1999: In /etc/rc, use mktemp(1) for
1.97      deraadt   495:        motd re-writing and change the find(1) to use -execdir
                    496:        (patch included).</a>
1.117     deraadt   497: <li><a href=errata25.html#chflags>Jul 30, 1999: Do not permit regular
1.95      deraadt   498:        users to chflags(2) or fchflags(2) on character or block devices
                    499:        which they may currently be the owner of (patch included).</a>
1.117     deraadt   500: <li><a href=errata25.html#nroff>Jul 27, 1999: Cause groff(1) to be invoked
1.95      deraadt   501:        with the -S flag, when called by nroff(1) (patch included).</a>
1.93      deraadt   502: </ul>
                    503:
1.106     deraadt   504: <p>
                    505: <li>
1.75      deraadt   506: <a name=24></a>
1.110     deraadt   507: <h3><font color=#e00000>OpenBSD 2.4 Security Advisories</font></h3>
1.75      deraadt   508: These are the OpenBSD 2.4 advisories -- all these problems are solved
                    509: in <a href=anoncvs.html>OpenBSD current</a>.  Obviously, all the
                    510: OpenBSD 2.3 advisories listed below are fixed in OpenBSD 2.4.
                    511:
1.96      deraadt   512: <p>
1.75      deraadt   513: <ul>
1.92      deraadt   514: <li><a href=errata24.html#poll>Mar 22, 1999: The nfds argument for poll(2) needs
1.91      deraadt   515:        to be constrained, to avoid kvm starvation (patch included).</a>
1.92      deraadt   516: <li><a href=errata24.html#tss>Mar 21, 1999: A change in TSS handling stops
1.91      deraadt   517:        another kernel crash case caused by the <strong>crashme</strong>
                    518:        program (patch included).</a>
1.92      deraadt   519: <li><a href=errata24.html#nlink>Feb 25, 1999: An unbounded increment on the
1.90      deraadt   520:        nlink value in FFS and EXT2FS filesystems can cause a system crash.
1.89      deraadt   521:        (patch included).</a>
1.92      deraadt   522: <li><a href=errata24.html#ping>Feb 23, 1999: Yet another buffer overflow
1.88      deraadt   523:        existed in ping(8). (patch included).</a>
1.92      deraadt   524: <li><a href=errata24.html#ipqrace>Feb 19, 1999: ipintr() had a race in use of
1.87      deraadt   525:        the ipq, which could permit an attacker to cause a crash.
                    526:        (patch included).</a>
1.92      deraadt   527: <li><a href=errata24.html#accept>Feb 17, 1999: A race condition in the
1.86      deraadt   528:        kernel between accept(2) and select(2) could permit an attacker
                    529:        to hang sockets from remote.
                    530:        (patch included).</a>
1.92      deraadt   531: <li><a href=errata24.html#maxqueue>Feb 17, 1999: IP fragment assembly can
1.85      deraadt   532:        bog the machine excessively and cause problems.
                    533:        (patch included).</a>
1.92      deraadt   534: <li><a href=errata24.html#trctrap>Feb 12, 1999: i386 T_TRCTRAP handling and
1.84      deraadt   535:        DDB interacted to possibly cause a crash.
                    536:        (patch included).</a>
1.92      deraadt   537: <li><a href=errata24.html#rst>Feb 11, 1999: TCP/IP RST handling was sloppy.
1.83      deraadt   538:        (patch included).</a>
1.92      deraadt   539: <li><a href=errata24.html#bootpd>Nov 27, 1998: There is a remotely exploitable
1.81      deraadt   540:        problem in bootpd(8). (patch included).</a>
1.92      deraadt   541: <li><a href=errata24.html#termcap>Nov 19, 1998: There is a possibly locally
1.82      deraadt   542:        exploitable problem relating to environment variables in termcap
                    543:        and curses. (patch included).</a>
1.92      deraadt   544: <li><a href=errata24.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
1.78      deraadt   545:        bug in the TCP decoding kernel. (patch included).</a>
1.75      deraadt   546: </ul>
                    547:
1.106     deraadt   548: <p>
                    549: <li>
1.58      deraadt   550: <a name=23></a>
1.110     deraadt   551: <h3><font color=#e00000>OpenBSD 2.3 Security Advisories</font></h3>
1.73      deraadt   552: These are the OpenBSD 2.3 advisories -- all these problems are solved
                    553: in <a href=anoncvs.html>OpenBSD current</a>.  Obviously, all the
                    554: OpenBSD 2.2 advisories listed below are fixed in OpenBSD 2.3.
1.53      matthieu  555:
1.96      deraadt   556: <p>
1.53      matthieu  557: <ul>
1.81      deraadt   558: <li><a href=errata23.html#bootpd>Nov 27, 1998: There is a remotely exploitable
                    559:        problem in bootpd(8). (patch included).</a>
1.78      deraadt   560: <li><a href=errata23.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
                    561:        bug in the TCP decoding kernel. (patch included).</a>
1.190     mpech     562: <li><a href=errata23.html#resolver>August 31, 1998: A benign looking resolver
                    563:        buffer overflow bug was re-introduced accidentally (patches included).</a>
                    564: <li><a href=errata23.html#chpass>Aug 2, 1998:
                    565:        chpass(1) has a file descriptor leak which allows an
                    566:        attacker to modify /etc/master.passwd.</a>
                    567: <li><a href=errata23.html#inetd>July 15, 1998: Inetd had a file descriptor leak.</a>
1.76      aaron     568: <li><a href=errata23.html#fdalloc>Jul  2, 1998: setuid and setgid processes
1.72      deraadt   569:        should not be executed with fd slots 0, 1, or 2 free.
                    570:        (patch included).</a>
1.76      aaron     571: <li><a href=errata23.html#xlib>June 6, 1998: Further problems with the X
1.71      deraadt   572:        libraries (patches included).</a>
1.76      aaron     573: <li><a href=errata23.html#kill>May 17, 1998: kill(2) of setuid/setgid target
1.66      deraadt   574:        processes too permissive (4th revision patch included).</a>
1.76      aaron     575: <li><a href=errata23.html#immutable>May 11, 1998: mmap() permits partial bypassing
1.60      deraadt   576:        of immutable and append-only file flags. (patch included).</a>
1.190     mpech     577: <li><a href=errata23.html#ipsec>May  5, 1998: Incorrect handling of IPSEC packets
                    578:        if IPSEC is enabled (patch included).</a>
1.76      aaron     579: <li><a href=errata23.html#xterm-xaw>May  1, 1998: Buffer overflow in xterm and Xaw
1.58      deraadt   580:        (CERT advisory VB-98.04) (patch included).</a>
1.53      matthieu  581: </ul>
1.9       deraadt   582:
1.106     deraadt   583: <p>
                    584: <li>
1.58      deraadt   585: <a name=22></a>
1.110     deraadt   586: <h3><font color=#e00000>OpenBSD 2.2 Security Advisories</font></h3>
1.45      deraadt   587: These are the OpenBSD 2.2 advisories.  All these problems are solved
1.55      deraadt   588: in <a href=23.html>OpenBSD 2.3</a>.  Some of these problems
1.45      deraadt   589: still exist in other operating systems.  (The supplied patches are for
                    590: OpenBSD 2.2; they may or may not work on OpenBSD 2.1).
1.9       deraadt   591:
1.96      deraadt   592: <p>
1.9       deraadt   593: <ul>
1.72      deraadt   594: <li><a href=errata22.html#ipsec>May  5, 1998: Incorrect handling of IPSEC
                    595:        packets if IPSEC is enabled (patch included).</a>
                    596: <li><a href=errata22.html#xterm-xaw>May  1, 1998: Buffer overflow in xterm
                    597:        and Xaw (CERT advisory VB-98.04) (patch included).</a>
                    598: <li><a href=errata22.html#uucpd>Apr 22, 1998: Buffer overflow in uucpd
                    599:        (patch included).</a>
                    600: <li><a href=errata22.html#rmjob>Apr 22, 1998: Buffer mismanagement in lprm
                    601:        (patch included).</a>
                    602: <li><a href=errata22.html#ping>Mar 31, 1998: Overflow in ping -R (patch included).</a>
                    603: <li><a href=errata22.html#named>Mar 30, 1998: Overflow in named fake-iquery
1.59      deraadt   604:        (patch included).</a>
1.72      deraadt   605: <li><a href=errata22.html#mountd>Mar  2, 1998: Accidental NFS filesystem
                    606:        export (patch included).</a>
1.112     philen    607: <li><a href="advisories/mmap.txt">Feb 26, 1998: Read-write mmap() flaw.</a>
1.72      deraadt   608:        Revision 3 of the patch is available <a href=errata22.html#mmap>here</a>
1.112     philen    609: <li><a href="advisories/sourceroute.txt">Feb 19, 1998: Sourcerouted Packet
1.59      deraadt   610:        Acceptance.</a>
1.50      deraadt   611:        A patch is available <a href=errata22.html#sourceroute>here</a>.
1.122     rohee     612: <li><a href=errata22.html#ruserok>Feb 13, 1998: Setuid coredump &amp; Ruserok()
1.72      deraadt   613:        flaw (patch included).</a>
                    614: <li><a href=errata22.html#ldso>Feb  9, 1998: MIPS ld.so flaw (patch included).</a>
1.1       deraadt   615: </ul>
                    616:
1.106     deraadt   617: <p>
                    618: <li>
1.58      deraadt   619: <a name=21></a>
1.110     deraadt   620: <h3><font color=#e00000>OpenBSD 2.1 Security Advisories</font></h3>
1.52      deraadt   621: These are the OpenBSD 2.1 advisories.  All these problems are solved
                    622: in <a href=22.html>OpenBSD 2.2</a>.  Some of these problems still
                    623: exist in other operating systems.  (If you are running OpenBSD 2.1, we
                    624: would strongly recommend an upgrade to the newest release, as this
                    625: patch list only attempts at fixing the most important security
                    626: problems.  In particular, OpenBSD 2.2 fixes numerous localhost
                    627: security problems.  Many of those problems were solved in ways which
                    628: make it hard for us to provide patches).
                    629:
1.96      deraadt   630: <p>
1.52      deraadt   631: <ul>
1.112     philen    632: <li><a href="advisories/signals.txt">Sep 15, 1997: Deviant Signals (patch included)</a>
                    633: <li><a href="advisories/rfork.txt">Aug  2, 1997: Rfork() system call flaw
1.59      deraadt   634:        (patch included)</a>
1.112     philen    635: <li><a href="advisories/procfs.txt">Jun 24, 1997: Procfs flaws (patch included)</a>
1.52      deraadt   636: </ul>
1.51      deraadt   637:
1.106     deraadt   638: <p>
                    639: <li>
                    640: <a name=20></a>
1.110     deraadt   641: <h3><font color=#e00000>OpenBSD 2.0 Security Advisories</font></h3>
1.99      deraadt   642: These are the OpenBSD 2.0 advisories.  All these problems are solved
                    643: in <a href=21.html>OpenBSD 2.1</a>.  Some of these problems still
                    644: exist in other operating systems.  (If you are running OpenBSD 2.0, we
                    645: commend you for being there back in the old days!, but you're really
                    646: missing out if you don't install a new version!)
                    647:
                    648: <p>
                    649: <ul>
1.112     philen    650: <li><a href="advisories/res_random.txt">April 22, 1997: Predictable IDs in the
1.99      deraadt   651:        resolver (patch included)</a>
                    652: <li>Many others... if people can hunt them down, please let me know
                    653:        and we'll put them up here.
                    654: </ul>
                    655:
1.106     deraadt   656: </dl>
1.51      deraadt   657: <p>
1.106     deraadt   658:
                    659: <a name=watching></a>
1.110     deraadt   660: <li><h3><font color=#e00000>Watching our Changes</font></h3><p>
1.106     deraadt   661:
1.21      deraadt   662: Since we take a proactive stance with security, we are continually
                    663: finding and fixing new security problems.  Not all of these problems
1.80      espie     664: get widely reported because (as stated earlier) many of them are not
1.45      deraadt   665: confirmed to be exploitable; many simple bugs we fix do turn out to
                    666: have security consequences we could not predict.  We do not have the
                    667: time resources to make these changes available in the above format.<p>
1.21      deraadt   668:
                    669: Thus there are usually minor security fixes in the current source code
                    670: beyond the previous major OpenBSD release.  We make a limited
1.45      deraadt   671: guarantee that these problems are of minimal impact and unproven
1.44      ian       672: exploitability.  If we discover that a problem definitely matters for
1.45      deraadt   673: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21      deraadt   674:
1.45      deraadt   675: People who are really concerned with security can do a number of
                    676: things:<p>
1.21      deraadt   677:
                    678: <ul>
                    679: <li>If you understand security issues, watch our
1.27      deraadt   680:        <a href=mail.html>source-changes mailing list</a> and keep an
1.23      deraadt   681:        eye out for things which appear security related.  Since
1.21      deraadt   682:        exploitability is not proven for many of the fixes we make,
                    683:        do not expect the relevant commit message to say "SECURITY FIX!".
                    684:        If a problem is proven and serious, a patch will be available
                    685:        here very shortly after.
1.161     horacio   686: <li>In addition to source changes, you can watch our <a href="mail.html">
1.160     ericj     687:        security-announce mailing list</a> which will notify you for every
1.186     ian       688:        security related item that the OpenBSD team deems as a possible threat,
1.160     ericj     689:        and instruct you on how to patch the problem.
1.21      deraadt   690: <li>Track our current source code tree, and teach yourself how to do a
1.29      deraadt   691:        complete system build from time to time (read /usr/src/Makefile
                    692:        carefully).  Users can make the assumption that the current
                    693:        source tree always has stronger security than the previous release.
1.45      deraadt   694:        However, building your own system from source code is not trivial;
                    695:        it is nearly 300MB of source code, and problems do occur as we
                    696:        transition between major releases.
1.115     ericj     697: <li>Install a binary snapshot for your
1.80      espie     698:        architecture, which are made available fairly often.  For
1.29      deraadt   699:        instance, an i386 snapshot is typically made available weekly.
1.21      deraadt   700: </ul>
                    701:
1.9       deraadt   702: <p>
1.153     jufi      703: <a name=reporting></a>
1.110     deraadt   704: <li><h3><font color=#e00000>Reporting problems</font></h3><p>
1.3       deraadt   705:
1.5       deraadt   706: <p> If you find a new security problem, you can mail it to
1.6       deraadt   707: <a href=mailto:deraadt@openbsd.org>deraadt@openbsd.org</a>.
1.7       deraadt   708: <br>
1.5       deraadt   709: If you wish to PGP encode it (but please only do so if privacy is very
1.112     philen    710: urgent, since it is inconvenient) use this <a href="advisories/pgpkey.txt">pgp key</a>.
1.5       deraadt   711:
1.107     deraadt   712: <p>
                    713: <a name=papers></a>
1.110     deraadt   714: <li><h3><font color=#e00000>Further Reading</font></h3><p>
1.107     deraadt   715:
                    716: A number of papers have been written by OpenBSD team members, about security
                    717: related changes they have done in OpenBSD.  The postscript versions of these
1.108     deraadt   718: documents are available as follows.<p>
1.107     deraadt   719:
                    720: <ul>
1.113     deraadt   721: <li>A Future-Adaptable Password Scheme.<br>
1.118     deraadt   722:     <a href=events.html#usenix99>Usenix 1999</a>,
1.153     jufi      723:     by <a href=mailto:provos@openbsd.org>Niels Provos</a>,
1.113     deraadt   724:     <a href=mailto:dm@openbsd.org>David Mazieres</a>.<br>
1.107     deraadt   725:     <a href=papers/bcrypt-paper.ps>paper</a> and
                    726:     <a href=papers/bcrypt-slides.ps>slides</a>.
1.113     deraadt   727: <p>
                    728: <li>Cryptography in OpenBSD: An Overview.<br>
1.118     deraadt   729:     <a href=events.html#usenix99>Usenix 1999</a>,
1.113     deraadt   730:     by <a href=mailto:deraadt@openbsd.org>Theo de Raadt</a>,
                    731:     <a href=mailto:niklas@openbsd.org>Niklas Hallqvist</a>,
                    732:     <a href=mailto:art@openbsd.org>Artur Grabowski</a>,
                    733:     <a href=mailto:angelos@openbsd.org>Angelos D. Keromytis</a>,
                    734:     <a href=mailto:provos@openbsd.org>Niels Provos</a>.<br>
1.107     deraadt   735:     <a href=papers/crypt-paper.ps>paper</a> and
                    736:     <a href=papers/crypt-slides.ps>slides</a>.
1.113     deraadt   737: <p>
                    738: <li>strlcpy and strlcat -- consistent, safe, string copy and concatenation.<br>
1.118     deraadt   739:     <a href=events.html#usenix99>Usenix 1999</a>,
1.113     deraadt   740:     by <a href=mailto:millert@openbsd.org>Todd C. Miller</a>,
                    741:     <a href=mailto:deraadt@openbsd.org>Theo de Raadt</a>.<br>
1.109     deraadt   742:     <a href=papers/strlcpy-paper.ps>paper</a> and
                    743:     <a href=papers/strlcpy-slides.ps>slides</a>.
1.113     deraadt   744: <p>
1.118     deraadt   745: <li>Dealing with Public Ethernet Jacks-Switches, Gateways, and Authentication.<br>
                    746:     <a href=events.html#lisa99>LISA 1999</a>,
                    747:     by <a href=mailto:beck@openbsd.org>Bob Beck</a>.<br>
                    748:     <a href=papers/authgw-paper.ps>paper</a> and
                    749:     <a href=papers/authgw-slides.ps>slides</a>.
                    750: <p>
1.153     jufi      751: <li>Encrypting Virtual Memory<br>
1.142     deraadt   752:     <a href=events.html#sec2000>Usenix Security 2000</a>,
                    753:     <a href=mailto:provos@openbsd.org>Niels Provos</a>.<br>
1.143     provos    754:     <a href=papers/swapencrypt.ps>paper</a> and
                    755:     <a href=papers/swapencrypt-slides.ps>slides</a>.
1.142     deraadt   756: <p>
1.107     deraadt   757: </ul>
                    758:
1.106     deraadt   759: </dl>
                    760:
1.2       deraadt   761: <hr>
1.68      pauls     762: <a href=index.html><img height=24 width=24 src=back.gif border=0 alt=OpenBSD></a>
1.24      deraadt   763: <a href=mailto:www@openbsd.org>www@openbsd.org</a>
                    764: <br>
1.194   ! mpech     765: <small>$OpenBSD: security.html,v 1.193 2002/01/29 22:08:37 horacio Exp $</small>
1.1       deraadt   766:
1.24      deraadt   767: </body>
                    768: </html>