Annotation of www/security.html, Revision 1.202
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1.20 deraadt 4: <title>OpenBSD Security</title>
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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
1.196 jufi 71: <a href="http://online.securityfocus.com/archive/1">
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
1.197 jufi 118: <a href="http://online.securityfocus.com/archive/1">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
1.197 jufi 132: <a href="http://online.securityfocus.com/archive/1">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->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>
1.202 ! millert 196: <li><a href=errata.html#mail>April 11, 2002:
! 197: The mail(1) was interpreting tilde escapes even when invoked
! 198: in non-interactive mode. As mail(1) is called as root from cron,
! 199: this can lead to a local root compromise.</a>
1.201 millert 200: <li><a href=errata.html#approval>March 19, 2002:
201: Under certain conditions, on systems using YP with netgroups in
202: the password database, it is possible for the rexecd(8) and rshd(8)
203: daemons to execute a shell from a password database entry for a
204: different user. Similarly, atrun(8) may change to the wrong
205: home directory when running jobs.</a>
1.200 millert 206: <li><a href=errata.html#zlib>March 13, 2002:
207: A potential double free() exists in the zlib library;
208: this is not exploitable on OpenBSD.
209: The kernel also contains a copy of zlib; it is not
210: currently known if the kernel zlib is exploitable.</a>
1.198 millert 211: <li><a href=errata.html#openssh>March 8, 2002:
212: An off-by-one check in OpenSSH's channel forwarding code
1.199 jufi 213: may allow a local user to gain super-user privileges.</a>
1.192 jason 214: <li><a href=errata.html#ptrace>January 21, 2002:
215: A race condition between the ptrace(2) and execve(2) system calls
216: allows an attacker to modify the memory contents of suid/sgid
217: processes which could lead to compromise of the super-user account.</a>
1.191 millert 218: <li><a href=errata.html#sudo>January 17, 2002:
219: There is a security hole in sudo(8) that can be exploited
220: when the Postfix sendmail replacement is installed that may
221: allow an attacker on the local host to gain root privileges.</a>
1.189 millert 222: <li><a href=errata.html#lpd>November 28, 2001:
223: An attacker can trick a machine running the lpd daemon into
224: creating new files in the root directory from a machine with
225: remote line printer access.</a>
1.188 millert 226: <li><a href=errata.html#vi.recover>November 13, 2001:
227: The vi.recover script can be abused in such a way as
228: to cause arbitrary zero-length files to be removed.</a>
1.190 mpech 229: <li><a href=errata.html#pf>November 13, 2001:
230: pf(4) was incapable of dealing with certain ipv6 icmp packets,
231: resulting in a crash.</a>
232: <li><a href=errata.html#sshd>November 12, 2001:
233: A security hole that may allow an attacker to partially authenticate
234: if -- and only if -- the administrator has enabled KerberosV.</a>
1.187 deraadt 235: </ul>
236:
237: <p>
238: <li>
1.173 deraadt 239: <a name=29></a>
240:
241: <h3><font color=#e00000>OpenBSD 2.9 Security Advisories</font></h3>
242: These are the OpenBSD 2.9 advisories -- all these problems are solved
243: in <a href=anoncvs.html>OpenBSD current</a> and the
1.179 jufi 244: <a href=stable.html>patch branch</a>.
1.173 deraadt 245:
246: <p>
247: <ul>
1.202 ! millert 248: <li><a href=errata29.html#mail>April 11, 2002:
! 249: The mail(1) was interpreting tilde escapes even when invoked
! 250: in non-interactive mode. As mail(1) is called as root from cron,
! 251: this can lead to a local root compromise.</a>
1.200 millert 252: <li><a href=errata29.html#zlib>March 13, 2002:
253: A potential double free() exists in the zlib library;
254: this is not exploitable on OpenBSD.
255: The kernel also contains a copy of zlib; it is not
256: currently known if the kernel zlib is exploitable.</a>
1.198 millert 257: <li><a href=errata29.html#openssh>March 8, 2002:
258: An off-by-one check in OpenSSH's channel forwarding code
1.199 jufi 259: may allow a local user to gain super-user privileges.</a>
1.198 millert 260: <li><a href=errata29.html#ptrace>January 21, 2002:
261: A race condition between the ptrace(2) and execve(2) system calls
262: allows an attacker to modify the memory contents of suid/sgid
263: processes which could lead to compromise of the super-user account.</a>
1.191 millert 264: <li><a href=errata29.html#sudo>January 17, 2002:
265: There is a security hole in sudo(8) that can be exploited
266: when the Postfix sendmail replacement is installed that may
267: allow an attacker on the local host to gain root privileges.</a>
1.189 millert 268: <li><a href=errata29.html#lpd2>November 28, 2001:
269: An attacker can trick a machine running the lpd daemon into
270: creating new files in the root directory from a machine with
271: remote line printer access.</a>
1.190 mpech 272: <li><a href=errata29.html#vi.recover>November 13, 2001:
273: The vi.recover script can be abused in such a way as
274: to cause arbitrary zero-length files to be removed.</a>
1.185 deraadt 275: <li><a href=errata29.html#uucp>September 11, 2001:
1.184 millert 276: A security hole exists in uuxqt(8) that may allow an
277: attacker to gain root privileges.</a>
1.185 deraadt 278: <li><a href=errata29.html#lpd>August 29, 2001:
1.183 millert 279: A security hole exists in lpd(8) that may allow an
280: attacker to gain root privileges if lpd is running.</a>
1.185 deraadt 281: <li><a href=errata29.html#sendmail2>August 21, 2001:
1.181 millert 282: A security hole exists in sendmail(8) that may allow an
283: attacker on the local host to gain root privileges.</a>
1.185 deraadt 284: <li><a href=errata29.html#nfs>July 30, 2001:
1.180 jason 285: A kernel buffer overflow in the NFS code can be used to execute
286: arbitrary code by users with mount privileges (only root by
1.181 millert 287: default).</a>
1.185 deraadt 288: <li><a href=errata29.html#kernexec>June 15, 2001:
1.178 aaron 289: A race condition in the kernel can lead to local root compromise.</a>
1.185 deraadt 290: <li><a href=errata29.html#sshcookie>June 12, 2001:
1.177 markus 291: sshd(8) allows users to delete arbitrary files named "cookies"
292: if X11 forwarding is enabled. X11 forwarding is disabled
293: by default.</a>
1.185 deraadt 294: <li><a href=errata29.html#fts>May 30, 2001:
1.176 millert 295: Programs using the fts routines can be tricked into changing
296: into the wrong directory.</a>
1.185 deraadt 297: <li><a href=errata29.html#sendmail>May 29, 2001:
1.174 millert 298: Sendmail signal handlers contain unsafe code,
299: leading to numerous race conditions.</a>
1.173 deraadt 300: </ul>
301:
302: <p>
303: <li>
1.152 deraadt 304: <a name=28></a>
305:
306: <h3><font color=#e00000>OpenBSD 2.8 Security Advisories</font></h3>
307: These are the OpenBSD 2.8 advisories -- all these problems are solved
1.154 millert 308: in <a href=anoncvs.html>OpenBSD current</a> and the
1.179 jufi 309: <a href=stable.html>patch branch</a>.
1.152 deraadt 310:
311: <p>
312: <ul>
1.184 millert 313: <li><a href=errata28.html#uucp>September 11, 2001:
314: A security hole exists in uuxqt(8) that may allow an
315: attacker to gain root privileges.</a>
1.183 millert 316: <li><a href=errata28.html#lpd>August 29, 2001:
317: A security hole exists in lpd(8) that may allow an
318: attacker to gain root privileges if lpd is running.</a>
1.181 millert 319: <li><a href=errata28.html#sendmail2>August 21, 2001:
320: A security hole exists in sendmail(8) that may allow an
321: attacker on the local host to gain root privileges.</a>
1.178 aaron 322: <li><a href=errata28.html#kernexec>June 15, 2001:
323: A race condition in the kernel can lead to local root compromise.</a>
1.176 millert 324: <li><a href=errata28.html#fts>May 30, 2001:
325: Programs using the fts routines can be tricked into changing
326: into the wrong directory.</a>
1.175 millert 327: <li><a href=errata28.html#sendmail>May 29, 2001:
328: Sendmail signal handlers contain unsafe code,
329: leading to numerous race conditions.</a>
1.173 deraadt 330: <li><a href=errata28.html#ipf_frag>Apr 23, 2001:
1.172 ericj 331: IPF contains a serious bug with its handling of fragment cacheing.</a>
1.173 deraadt 332: <li><a href=errata28.html#glob_limit>Apr 23, 2001:
1.172 ericj 333: ftpd(8) contains a potential DoS relating to glob(3).</a>
1.173 deraadt 334: <li><a href=errata28.html#glob>Apr 10, 2001:
1.170 ericj 335: The glob(3) library call contains multiple buffer overflows.</a>
1.173 deraadt 336: <li><a href=errata28.html#readline>Mar 18, 2001:
1.169 millert 337: The readline library creates history files with permissive modes based on the user's umask.</a>
1.173 deraadt 338: <li><a href=errata28.html#ipsec_ah>Mar 2, 2001:
1.167 ericj 339: Insufficient checks in the IPSEC AH IPv4 option handling code can lead to a buffer overrun in the kernel.</a>
1.173 deraadt 340: <li><a href=errata28.html#userldt>Mar 2, 2001:
1.168 horacio 341: The <b>USER_LDT</b> kernel option allows an attacker to gain access to privileged areas of kernel memory.</a>
1.173 deraadt 342: <li><a href=errata28.html#sudo>Feb 22, 2001:
1.171 millert 343: a non-exploitable buffer overflow was fixed in sudo(8).</a>
1.173 deraadt 344: <li><a href=errata28.html#named>Jan 29, 2001:
1.163 jason 345: merge named(8) with ISC BIND 4.9.8-REL, which fixes some buffer vulnerabilities.</a>
1.173 deraadt 346: <li><a href=errata28.html#rnd>Jan 22, 2001:
1.162 jason 347: rnd(4) did not use all of its input when written to.</a>
1.173 deraadt 348: <li><a href=errata28.html#xlock>Dec 22, 2000:
1.159 ericj 349: xlock(1)'s authentication was re-done to authenticate via a named pipe. (patch and new xlock binaries included).</a>
1.173 deraadt 350: <li><a href=errata28.html#procfs>Dec 18, 2000:
1.157 ericj 351: Procfs contains numerous overflows. Procfs is not used by default in OpenBSD. (patch included).</a>
1.173 deraadt 352: <li><a href=errata28.html#kerberos2>Dec 10, 2000:
1.156 deraadt 353: Another problem exists in KerberosIV libraries (patch included).</a>
1.173 deraadt 354: <li><a href=errata28.html#kerberos>Dec 7, 2000:
1.155 deraadt 355: A set of problems in KerberosIV exist (patch included).</a>
1.173 deraadt 356: <li><a href=errata28.html#ftpd>Dec 4, 2000:
1.154 millert 357: A single-byte buffer overflow exists in ftpd (patch included).</a>
1.152 deraadt 358: </ul>
359:
360: <p>
361: <li>
1.124 deraadt 362: <a name=27></a>
363:
364: <h3><font color=#e00000>OpenBSD 2.7 Security Advisories</font></h3>
365: These are the OpenBSD 2.7 advisories -- all these problems are solved
366: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
367: OpenBSD 2.6 advisories listed below are fixed in OpenBSD 2.7.
368:
369: <p>
370: <ul>
1.169 millert 371: <li><a href=errata27.html#readline>Mar 18, 2001:
372: The readline library creates history files with permissive modes based on the user's umask.</a>
373: <li><a href=errata27.html#sudo>Feb 22, 2001:
374: a buffer overflow was fixed in sudo(8).</a>
1.154 millert 375: <li><a href=errata27.html#ftpd>Dec 4, 2000:
376: A single-byte buffer overflow exists in ftpd (patch included).</a>
1.152 deraadt 377: <li><a href=errata27.html#sshforwarding>Nov 10, 2000:
378: Hostile servers can force OpenSSH clients to do agent or X11 forwarding.
379: (patch included)</a>
380: <li><a href=errata27.html#xtrans>Oct 26, 2000:
1.151 matthieu 381: X11 libraries have 2 potential overflows in xtrans code.
382: (patch included)</a>
1.152 deraadt 383: <li><a href=errata27.html#httpd>Oct 18, 2000:
1.150 beck 384: Apache mod_rewrite and mod_vhost_alias modules could expose files
385: on the server in certain configurations if used.
386: (patch included)</a>
1.164 deraadt 387: <li><a href=errata27.html#telnetd>Oct 10, 2000:
1.149 millert 388: The telnet daemon does not strip out the TERMINFO, TERMINFO_DIRS,
389: TERMPATH and TERMCAP environment variables as it should.
390: (patch included)</a>
1.152 deraadt 391: <li><a href=errata27.html#format_strings>Oct 6, 2000:
1.148 millert 392: There are printf-style format string bugs in several privileged
393: programs. (patch included)</a>
1.152 deraadt 394: <li><a href=errata27.html#curses>Oct 6, 2000:
1.147 millert 395: libcurses honored terminal descriptions in the $HOME/.terminfo
396: directory as well as in the TERMCAP environment variable for
397: setuid and setgid applications.
1.146 deraadt 398: (patch included)</a>
1.152 deraadt 399: <li><a href=errata27.html#talkd>Oct 6, 2000:
1.146 deraadt 400: A format string vulnerability exists in talkd(8).
401: (patch included)</a>
1.152 deraadt 402: <li><a href=errata27.html#pw_error>Oct 3, 2000:
1.145 aaron 403: A format string vulnerability exists in the pw_error() function of the
404: libutil library, yielding localhost root through chpass(1).
405: (patch included)</a>
1.152 deraadt 406: <li><a href=errata27.html#ipsec>Sep 18, 2000:
1.144 jason 407: Bad ESP/AH packets could cause a crash under certain conditions.
408: (patch included)</a>
1.152 deraadt 409: <li><a href=errata27.html#xlock>Aug 16, 2000:
1.141 deraadt 410: A format string vulnerability (localhost root) exists in xlock(1).
411: (patch included)</a>
1.152 deraadt 412: <li><a href=errata27.html#X11_libs>July 14, 2000:
1.139 deraadt 413: Various bugs found in X11 libraries have various side effects, almost
414: completely denial of service in OpenBSD.
415: (patch included)</a>
1.152 deraadt 416: <li><a href=errata27.html#ftpd>July 5, 2000:
1.136 deraadt 417: Just like pretty much all the other unix ftp daemons
418: on the planet, ftpd had a remote root hole in it.
419: Luckily, ftpd was not enabled by default.
1.137 deraadt 420: The problem exists if anonymous ftp is enabled.
1.136 deraadt 421: (patch included)</a>
1.152 deraadt 422: <li><a href=errata27.html#mopd>July 5, 2000:
1.136 deraadt 423: Mopd, very rarely used, contained some buffer overflows.
424: (patch included)</a>
1.152 deraadt 425: <li><a href=errata27.html#libedit>June 28, 2000:
1.135 deraadt 426: libedit would check for a <b>.editrc</b> file in the current
427: directory. Not known to be a real security issue, but a patch
428: is available anyways.
429: (patch included)</a>
1.152 deraadt 430: <li><a href=errata27.html#dhclient>June 24, 2000:
1.134 deraadt 431: A serious bug in dhclient(8) could allow strings from a
432: malicious dhcp server to be executed in the shell as root.
433: (patch included)</a>
1.152 deraadt 434: <li><a href=errata27.html#isakmpd>June 9, 2000:
1.133 deraadt 435: A serious bug in isakmpd(8) policy handling wherein
436: policy verification could be completely bypassed in isakmpd.
437: (patch included)</a>
1.152 deraadt 438: <li><a href=errata27.html#uselogin>June 6, 2000:
1.132 deraadt 439: The non-default flag UseLogin in <b>/etc/sshd_config</b> is broken,
440: should not be used, and results in security problems on
441: other operating systems.</a>
1.152 deraadt 442: <li><a href=errata27.html#bridge>May 26, 2000:
1.129 deraadt 443: The bridge(4) <i>learning</i> flag may be bypassed.
1.128 deraadt 444: (patch included)</a>
1.152 deraadt 445: <li><a href=errata27.html#ipf>May 25, 2000:
1.127 kjell 446: Improper use of ipf <i>keep-state</i> rules can result
447: in firewall rules being bypassed. (patch included)</a>
448:
1.124 deraadt 449: </ul>
450:
451: <p>
452: <li>
1.119 deraadt 453: <a name=26></a>
454:
455: <h3><font color=#e00000>OpenBSD 2.6 Security Advisories</font></h3>
456: These are the OpenBSD 2.6 advisories -- all these problems are solved
457: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
458: OpenBSD 2.5 advisories listed below are fixed in OpenBSD 2.6.
459:
460: <p>
461: <ul>
1.130 deraadt 462: <li><a href=errata26.html#semconfig>May 26, 2000:
463: SYSV semaphore support contained an undocumented system call
1.131 deraadt 464: which could wedge semaphore-using processes from exiting. (patch included)</a>
1.127 kjell 465: <li><a href=errata26.html#ipf>May 25, 2000:
466: Improper use of ipf <i>keep-state</i> rules can result
467: in firewall rules being bypassed. (patch included)</a>
1.126 deraadt 468: <li><a href=errata26.html#xlockmore>May 25, 2000:
1.125 deraadt 469: xlockmore has a bug which a localhost attacker can use to gain
470: access to the encrypted root password hash (which is normally
471: encoded using blowfish (see
472: <a href="http://www.openbsd.org/cgi-bin/man.cgi?query=crypt&sektion=3">
473: crypt(3)</a>)
474: (patch included).</a>
1.126 deraadt 475: <li><a href=errata26.html#procfs>Jan 20, 2000:
1.123 deraadt 476: Systems running with procfs enabled and mounted are
477: vulnerable to a very tricky exploit. procfs is not
478: mounted by default.
479: (patch included).</a>
1.190 mpech 480: <li><a href=errata26.html#sendmail>Dec 4, 1999:
481: Sendmail permitted any user to cause a aliases file wrap,
482: thus exposing the system to a race where the aliases file
483: did not exist.
1.119 deraadt 484: (patch included).</a>
1.190 mpech 485: <li><a href=errata26.html#poll>Dec 4, 1999:
486: Various bugs in poll(2) may cause a kernel crash.</a>
1.126 deraadt 487: <li><a href=errata26.html#sslUSA>Dec 2, 1999:
1.120 deraadt 488: A buffer overflow in the RSAREF code included in the
489: USA version of libssl, is possibly exploitable in
490: httpd, ssh, or isakmpd, if SSL/RSA features are enabled.
1.124 deraadt 491: (patch included).<br></a>
492: <strong>Update:</strong> Turns out that this was not exploitable
493: in any of the software included in OpenBSD 2.6.
1.190 mpech 494: <li><a href=errata26.html#ifmedia>Nov 9, 1999:
495: Any user could change interface media configurations, resulting in
496: a localhost denial of service attack.
1.121 deraadt 497: (patch included).</a>
1.119 deraadt 498: </ul>
499:
500: <p>
501: <li>
502:
1.93 deraadt 503: <a name=25></a>
1.106 deraadt 504:
1.110 deraadt 505: <h3><font color=#e00000>OpenBSD 2.5 Security Advisories</font></h3>
1.93 deraadt 506: These are the OpenBSD 2.5 advisories -- all these problems are solved
507: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
508: OpenBSD 2.4 advisories listed below are fixed in OpenBSD 2.5.
509:
1.96 deraadt 510: <p>
1.104 deraadt 511: <ul>
1.117 deraadt 512: <li><a href=errata25.html#cron>Aug 30, 1999:
1.103 deraadt 513: In cron(8), make sure argv[] is NULL terminated in the
514: fake popen() and run sendmail as the user, not as root.
515: (patch included).</a>
1.117 deraadt 516: <li><a href=errata25.html#miscfs>Aug 12, 1999: The procfs and fdescfs
1.101 deraadt 517: filesystems had an overrun in their handling of uio_offset
518: in their readdir() routines. (These filesystems are not
519: enabled by default). (patch included).</a>
1.117 deraadt 520: <li><a href=errata25.html#profil>Aug 9, 1999: Stop profiling (see profil(2))
1.100 deraadt 521: when we execve() a new process. (patch included).</a>
1.117 deraadt 522: <li><a href=errata25.html#ipsec_in_use>Aug 6, 1999: Packets that should have
1.98 deraadt 523: been handled by IPsec may be transmitted as cleartext.
524: PF_KEY SA expirations may leak kernel resources.
525: (patch included).</a>
1.117 deraadt 526: <li><a href=errata25.html#rc>Aug 5, 1999: In /etc/rc, use mktemp(1) for
1.97 deraadt 527: motd re-writing and change the find(1) to use -execdir
528: (patch included).</a>
1.117 deraadt 529: <li><a href=errata25.html#chflags>Jul 30, 1999: Do not permit regular
1.95 deraadt 530: users to chflags(2) or fchflags(2) on character or block devices
531: which they may currently be the owner of (patch included).</a>
1.117 deraadt 532: <li><a href=errata25.html#nroff>Jul 27, 1999: Cause groff(1) to be invoked
1.95 deraadt 533: with the -S flag, when called by nroff(1) (patch included).</a>
1.93 deraadt 534: </ul>
535:
1.106 deraadt 536: <p>
537: <li>
1.75 deraadt 538: <a name=24></a>
1.110 deraadt 539: <h3><font color=#e00000>OpenBSD 2.4 Security Advisories</font></h3>
1.75 deraadt 540: These are the OpenBSD 2.4 advisories -- all these problems are solved
541: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
542: OpenBSD 2.3 advisories listed below are fixed in OpenBSD 2.4.
543:
1.96 deraadt 544: <p>
1.75 deraadt 545: <ul>
1.92 deraadt 546: <li><a href=errata24.html#poll>Mar 22, 1999: The nfds argument for poll(2) needs
1.91 deraadt 547: to be constrained, to avoid kvm starvation (patch included).</a>
1.92 deraadt 548: <li><a href=errata24.html#tss>Mar 21, 1999: A change in TSS handling stops
1.91 deraadt 549: another kernel crash case caused by the <strong>crashme</strong>
550: program (patch included).</a>
1.92 deraadt 551: <li><a href=errata24.html#nlink>Feb 25, 1999: An unbounded increment on the
1.90 deraadt 552: nlink value in FFS and EXT2FS filesystems can cause a system crash.
1.89 deraadt 553: (patch included).</a>
1.92 deraadt 554: <li><a href=errata24.html#ping>Feb 23, 1999: Yet another buffer overflow
1.88 deraadt 555: existed in ping(8). (patch included).</a>
1.92 deraadt 556: <li><a href=errata24.html#ipqrace>Feb 19, 1999: ipintr() had a race in use of
1.87 deraadt 557: the ipq, which could permit an attacker to cause a crash.
558: (patch included).</a>
1.92 deraadt 559: <li><a href=errata24.html#accept>Feb 17, 1999: A race condition in the
1.86 deraadt 560: kernel between accept(2) and select(2) could permit an attacker
561: to hang sockets from remote.
562: (patch included).</a>
1.92 deraadt 563: <li><a href=errata24.html#maxqueue>Feb 17, 1999: IP fragment assembly can
1.85 deraadt 564: bog the machine excessively and cause problems.
565: (patch included).</a>
1.92 deraadt 566: <li><a href=errata24.html#trctrap>Feb 12, 1999: i386 T_TRCTRAP handling and
1.84 deraadt 567: DDB interacted to possibly cause a crash.
568: (patch included).</a>
1.92 deraadt 569: <li><a href=errata24.html#rst>Feb 11, 1999: TCP/IP RST handling was sloppy.
1.83 deraadt 570: (patch included).</a>
1.92 deraadt 571: <li><a href=errata24.html#bootpd>Nov 27, 1998: There is a remotely exploitable
1.81 deraadt 572: problem in bootpd(8). (patch included).</a>
1.92 deraadt 573: <li><a href=errata24.html#termcap>Nov 19, 1998: There is a possibly locally
1.82 deraadt 574: exploitable problem relating to environment variables in termcap
575: and curses. (patch included).</a>
1.92 deraadt 576: <li><a href=errata24.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
1.78 deraadt 577: bug in the TCP decoding kernel. (patch included).</a>
1.75 deraadt 578: </ul>
579:
1.106 deraadt 580: <p>
581: <li>
1.58 deraadt 582: <a name=23></a>
1.110 deraadt 583: <h3><font color=#e00000>OpenBSD 2.3 Security Advisories</font></h3>
1.73 deraadt 584: These are the OpenBSD 2.3 advisories -- all these problems are solved
585: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
586: OpenBSD 2.2 advisories listed below are fixed in OpenBSD 2.3.
1.53 matthieu 587:
1.96 deraadt 588: <p>
1.53 matthieu 589: <ul>
1.81 deraadt 590: <li><a href=errata23.html#bootpd>Nov 27, 1998: There is a remotely exploitable
591: problem in bootpd(8). (patch included).</a>
1.78 deraadt 592: <li><a href=errata23.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
593: bug in the TCP decoding kernel. (patch included).</a>
1.190 mpech 594: <li><a href=errata23.html#resolver>August 31, 1998: A benign looking resolver
595: buffer overflow bug was re-introduced accidentally (patches included).</a>
596: <li><a href=errata23.html#chpass>Aug 2, 1998:
597: chpass(1) has a file descriptor leak which allows an
598: attacker to modify /etc/master.passwd.</a>
599: <li><a href=errata23.html#inetd>July 15, 1998: Inetd had a file descriptor leak.</a>
1.76 aaron 600: <li><a href=errata23.html#fdalloc>Jul 2, 1998: setuid and setgid processes
1.72 deraadt 601: should not be executed with fd slots 0, 1, or 2 free.
602: (patch included).</a>
1.76 aaron 603: <li><a href=errata23.html#xlib>June 6, 1998: Further problems with the X
1.71 deraadt 604: libraries (patches included).</a>
1.76 aaron 605: <li><a href=errata23.html#kill>May 17, 1998: kill(2) of setuid/setgid target
1.66 deraadt 606: processes too permissive (4th revision patch included).</a>
1.76 aaron 607: <li><a href=errata23.html#immutable>May 11, 1998: mmap() permits partial bypassing
1.60 deraadt 608: of immutable and append-only file flags. (patch included).</a>
1.190 mpech 609: <li><a href=errata23.html#ipsec>May 5, 1998: Incorrect handling of IPSEC packets
610: if IPSEC is enabled (patch included).</a>
1.76 aaron 611: <li><a href=errata23.html#xterm-xaw>May 1, 1998: Buffer overflow in xterm and Xaw
1.58 deraadt 612: (CERT advisory VB-98.04) (patch included).</a>
1.53 matthieu 613: </ul>
1.9 deraadt 614:
1.106 deraadt 615: <p>
616: <li>
1.58 deraadt 617: <a name=22></a>
1.110 deraadt 618: <h3><font color=#e00000>OpenBSD 2.2 Security Advisories</font></h3>
1.45 deraadt 619: These are the OpenBSD 2.2 advisories. All these problems are solved
1.55 deraadt 620: in <a href=23.html>OpenBSD 2.3</a>. Some of these problems
1.45 deraadt 621: still exist in other operating systems. (The supplied patches are for
622: OpenBSD 2.2; they may or may not work on OpenBSD 2.1).
1.9 deraadt 623:
1.96 deraadt 624: <p>
1.9 deraadt 625: <ul>
1.72 deraadt 626: <li><a href=errata22.html#ipsec>May 5, 1998: Incorrect handling of IPSEC
627: packets if IPSEC is enabled (patch included).</a>
628: <li><a href=errata22.html#xterm-xaw>May 1, 1998: Buffer overflow in xterm
629: and Xaw (CERT advisory VB-98.04) (patch included).</a>
630: <li><a href=errata22.html#uucpd>Apr 22, 1998: Buffer overflow in uucpd
631: (patch included).</a>
632: <li><a href=errata22.html#rmjob>Apr 22, 1998: Buffer mismanagement in lprm
633: (patch included).</a>
634: <li><a href=errata22.html#ping>Mar 31, 1998: Overflow in ping -R (patch included).</a>
635: <li><a href=errata22.html#named>Mar 30, 1998: Overflow in named fake-iquery
1.59 deraadt 636: (patch included).</a>
1.72 deraadt 637: <li><a href=errata22.html#mountd>Mar 2, 1998: Accidental NFS filesystem
638: export (patch included).</a>
1.112 philen 639: <li><a href="advisories/mmap.txt">Feb 26, 1998: Read-write mmap() flaw.</a>
1.72 deraadt 640: Revision 3 of the patch is available <a href=errata22.html#mmap>here</a>
1.112 philen 641: <li><a href="advisories/sourceroute.txt">Feb 19, 1998: Sourcerouted Packet
1.59 deraadt 642: Acceptance.</a>
1.50 deraadt 643: A patch is available <a href=errata22.html#sourceroute>here</a>.
1.122 rohee 644: <li><a href=errata22.html#ruserok>Feb 13, 1998: Setuid coredump & Ruserok()
1.72 deraadt 645: flaw (patch included).</a>
646: <li><a href=errata22.html#ldso>Feb 9, 1998: MIPS ld.so flaw (patch included).</a>
1.1 deraadt 647: </ul>
648:
1.106 deraadt 649: <p>
650: <li>
1.58 deraadt 651: <a name=21></a>
1.110 deraadt 652: <h3><font color=#e00000>OpenBSD 2.1 Security Advisories</font></h3>
1.52 deraadt 653: These are the OpenBSD 2.1 advisories. All these problems are solved
654: in <a href=22.html>OpenBSD 2.2</a>. Some of these problems still
655: exist in other operating systems. (If you are running OpenBSD 2.1, we
656: would strongly recommend an upgrade to the newest release, as this
657: patch list only attempts at fixing the most important security
658: problems. In particular, OpenBSD 2.2 fixes numerous localhost
659: security problems. Many of those problems were solved in ways which
660: make it hard for us to provide patches).
661:
1.96 deraadt 662: <p>
1.52 deraadt 663: <ul>
1.112 philen 664: <li><a href="advisories/signals.txt">Sep 15, 1997: Deviant Signals (patch included)</a>
665: <li><a href="advisories/rfork.txt">Aug 2, 1997: Rfork() system call flaw
1.59 deraadt 666: (patch included)</a>
1.112 philen 667: <li><a href="advisories/procfs.txt">Jun 24, 1997: Procfs flaws (patch included)</a>
1.52 deraadt 668: </ul>
1.51 deraadt 669:
1.106 deraadt 670: <p>
671: <li>
672: <a name=20></a>
1.110 deraadt 673: <h3><font color=#e00000>OpenBSD 2.0 Security Advisories</font></h3>
1.99 deraadt 674: These are the OpenBSD 2.0 advisories. All these problems are solved
675: in <a href=21.html>OpenBSD 2.1</a>. Some of these problems still
676: exist in other operating systems. (If you are running OpenBSD 2.0, we
677: commend you for being there back in the old days!, but you're really
678: missing out if you don't install a new version!)
679:
680: <p>
681: <ul>
1.112 philen 682: <li><a href="advisories/res_random.txt">April 22, 1997: Predictable IDs in the
1.99 deraadt 683: resolver (patch included)</a>
684: <li>Many others... if people can hunt them down, please let me know
685: and we'll put them up here.
686: </ul>
687:
1.106 deraadt 688: </dl>
1.51 deraadt 689: <p>
1.106 deraadt 690:
691: <a name=watching></a>
1.110 deraadt 692: <li><h3><font color=#e00000>Watching our Changes</font></h3><p>
1.106 deraadt 693:
1.21 deraadt 694: Since we take a proactive stance with security, we are continually
695: finding and fixing new security problems. Not all of these problems
1.80 espie 696: get widely reported because (as stated earlier) many of them are not
1.45 deraadt 697: confirmed to be exploitable; many simple bugs we fix do turn out to
698: have security consequences we could not predict. We do not have the
699: time resources to make these changes available in the above format.<p>
1.21 deraadt 700:
701: Thus there are usually minor security fixes in the current source code
702: beyond the previous major OpenBSD release. We make a limited
1.45 deraadt 703: guarantee that these problems are of minimal impact and unproven
1.44 ian 704: exploitability. If we discover that a problem definitely matters for
1.45 deraadt 705: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21 deraadt 706:
1.45 deraadt 707: People who are really concerned with security can do a number of
708: things:<p>
1.21 deraadt 709:
710: <ul>
711: <li>If you understand security issues, watch our
1.27 deraadt 712: <a href=mail.html>source-changes mailing list</a> and keep an
1.23 deraadt 713: eye out for things which appear security related. Since
1.21 deraadt 714: exploitability is not proven for many of the fixes we make,
715: do not expect the relevant commit message to say "SECURITY FIX!".
716: If a problem is proven and serious, a patch will be available
717: here very shortly after.
1.161 horacio 718: <li>In addition to source changes, you can watch our <a href="mail.html">
1.160 ericj 719: security-announce mailing list</a> which will notify you for every
1.186 ian 720: security related item that the OpenBSD team deems as a possible threat,
1.160 ericj 721: and instruct you on how to patch the problem.
1.21 deraadt 722: <li>Track our current source code tree, and teach yourself how to do a
1.29 deraadt 723: complete system build from time to time (read /usr/src/Makefile
724: carefully). Users can make the assumption that the current
725: source tree always has stronger security than the previous release.
1.45 deraadt 726: However, building your own system from source code is not trivial;
727: it is nearly 300MB of source code, and problems do occur as we
728: transition between major releases.
1.115 ericj 729: <li>Install a binary snapshot for your
1.80 espie 730: architecture, which are made available fairly often. For
1.29 deraadt 731: instance, an i386 snapshot is typically made available weekly.
1.21 deraadt 732: </ul>
733:
1.9 deraadt 734: <p>
1.153 jufi 735: <a name=reporting></a>
1.110 deraadt 736: <li><h3><font color=#e00000>Reporting problems</font></h3><p>
1.3 deraadt 737:
1.5 deraadt 738: <p> If you find a new security problem, you can mail it to
1.6 deraadt 739: <a href=mailto:deraadt@openbsd.org>deraadt@openbsd.org</a>.
1.7 deraadt 740: <br>
1.5 deraadt 741: If you wish to PGP encode it (but please only do so if privacy is very
1.112 philen 742: urgent, since it is inconvenient) use this <a href="advisories/pgpkey.txt">pgp key</a>.
1.5 deraadt 743:
1.107 deraadt 744: <p>
745: <a name=papers></a>
1.110 deraadt 746: <li><h3><font color=#e00000>Further Reading</font></h3><p>
1.107 deraadt 747:
748: A number of papers have been written by OpenBSD team members, about security
749: related changes they have done in OpenBSD. The postscript versions of these
1.108 deraadt 750: documents are available as follows.<p>
1.107 deraadt 751:
752: <ul>
1.113 deraadt 753: <li>A Future-Adaptable Password Scheme.<br>
1.118 deraadt 754: <a href=events.html#usenix99>Usenix 1999</a>,
1.153 jufi 755: by <a href=mailto:provos@openbsd.org>Niels Provos</a>,
1.113 deraadt 756: <a href=mailto:dm@openbsd.org>David Mazieres</a>.<br>
1.107 deraadt 757: <a href=papers/bcrypt-paper.ps>paper</a> and
758: <a href=papers/bcrypt-slides.ps>slides</a>.
1.113 deraadt 759: <p>
760: <li>Cryptography in OpenBSD: An Overview.<br>
1.118 deraadt 761: <a href=events.html#usenix99>Usenix 1999</a>,
1.113 deraadt 762: by <a href=mailto:deraadt@openbsd.org>Theo de Raadt</a>,
763: <a href=mailto:niklas@openbsd.org>Niklas Hallqvist</a>,
764: <a href=mailto:art@openbsd.org>Artur Grabowski</a>,
765: <a href=mailto:angelos@openbsd.org>Angelos D. Keromytis</a>,
766: <a href=mailto:provos@openbsd.org>Niels Provos</a>.<br>
1.107 deraadt 767: <a href=papers/crypt-paper.ps>paper</a> and
768: <a href=papers/crypt-slides.ps>slides</a>.
1.113 deraadt 769: <p>
770: <li>strlcpy and strlcat -- consistent, safe, string copy and concatenation.<br>
1.118 deraadt 771: <a href=events.html#usenix99>Usenix 1999</a>,
1.113 deraadt 772: by <a href=mailto:millert@openbsd.org>Todd C. Miller</a>,
773: <a href=mailto:deraadt@openbsd.org>Theo de Raadt</a>.<br>
1.109 deraadt 774: <a href=papers/strlcpy-paper.ps>paper</a> and
775: <a href=papers/strlcpy-slides.ps>slides</a>.
1.113 deraadt 776: <p>
1.118 deraadt 777: <li>Dealing with Public Ethernet Jacks-Switches, Gateways, and Authentication.<br>
778: <a href=events.html#lisa99>LISA 1999</a>,
779: by <a href=mailto:beck@openbsd.org>Bob Beck</a>.<br>
780: <a href=papers/authgw-paper.ps>paper</a> and
781: <a href=papers/authgw-slides.ps>slides</a>.
782: <p>
1.153 jufi 783: <li>Encrypting Virtual Memory<br>
1.142 deraadt 784: <a href=events.html#sec2000>Usenix Security 2000</a>,
785: <a href=mailto:provos@openbsd.org>Niels Provos</a>.<br>
1.143 provos 786: <a href=papers/swapencrypt.ps>paper</a> and
787: <a href=papers/swapencrypt-slides.ps>slides</a>.
1.142 deraadt 788: <p>
1.107 deraadt 789: </ul>
790:
1.106 deraadt 791: </dl>
792:
1.2 deraadt 793: <hr>
1.68 pauls 794: <a href=index.html><img height=24 width=24 src=back.gif border=0 alt=OpenBSD></a>
1.24 deraadt 795: <a href=mailto:www@openbsd.org>www@openbsd.org</a>
796: <br>
1.202 ! millert 797: <small>$OpenBSD: security.html,v 1.201 2002/03/19 22:06:26 millert Exp $</small>
1.1 deraadt 798:
1.24 deraadt 799: </body>
800: </html>
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