Annotation of www/security.html, Revision 1.201
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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>
1.201 ! millert 196: <li><a href=errata.html#approval>March 19, 2002:
! 197: Under certain conditions, on systems using YP with netgroups in
! 198: the password database, it is possible for the rexecd(8) and rshd(8)
! 199: daemons to execute a shell from a password database entry for a
! 200: different user. Similarly, atrun(8) may change to the wrong
! 201: home directory when running jobs.</a>
1.200 millert 202: <li><a href=errata.html#zlib>March 13, 2002:
203: A potential double free() exists in the zlib library;
204: this is not exploitable on OpenBSD.
205: The kernel also contains a copy of zlib; it is not
206: currently known if the kernel zlib is exploitable.</a>
1.198 millert 207: <li><a href=errata.html#openssh>March 8, 2002:
208: An off-by-one check in OpenSSH's channel forwarding code
1.199 jufi 209: may allow a local user to gain super-user privileges.</a>
1.192 jason 210: <li><a href=errata.html#ptrace>January 21, 2002:
211: A race condition between the ptrace(2) and execve(2) system calls
212: allows an attacker to modify the memory contents of suid/sgid
213: processes which could lead to compromise of the super-user account.</a>
1.191 millert 214: <li><a href=errata.html#sudo>January 17, 2002:
215: There is a security hole in sudo(8) that can be exploited
216: when the Postfix sendmail replacement is installed that may
217: allow an attacker on the local host to gain root privileges.</a>
1.189 millert 218: <li><a href=errata.html#lpd>November 28, 2001:
219: An attacker can trick a machine running the lpd daemon into
220: creating new files in the root directory from a machine with
221: remote line printer access.</a>
1.188 millert 222: <li><a href=errata.html#vi.recover>November 13, 2001:
223: The vi.recover script can be abused in such a way as
224: to cause arbitrary zero-length files to be removed.</a>
1.190 mpech 225: <li><a href=errata.html#pf>November 13, 2001:
226: pf(4) was incapable of dealing with certain ipv6 icmp packets,
227: resulting in a crash.</a>
228: <li><a href=errata.html#sshd>November 12, 2001:
229: A security hole that may allow an attacker to partially authenticate
230: if -- and only if -- the administrator has enabled KerberosV.</a>
1.187 deraadt 231: </ul>
232:
233: <p>
234: <li>
1.173 deraadt 235: <a name=29></a>
236:
237: <h3><font color=#e00000>OpenBSD 2.9 Security Advisories</font></h3>
238: These are the OpenBSD 2.9 advisories -- all these problems are solved
239: in <a href=anoncvs.html>OpenBSD current</a> and the
1.179 jufi 240: <a href=stable.html>patch branch</a>.
1.173 deraadt 241:
242: <p>
243: <ul>
1.200 millert 244: <li><a href=errata29.html#zlib>March 13, 2002:
245: A potential double free() exists in the zlib library;
246: this is not exploitable on OpenBSD.
247: The kernel also contains a copy of zlib; it is not
248: currently known if the kernel zlib is exploitable.</a>
1.198 millert 249: <li><a href=errata29.html#openssh>March 8, 2002:
250: An off-by-one check in OpenSSH's channel forwarding code
1.199 jufi 251: may allow a local user to gain super-user privileges.</a>
1.198 millert 252: <li><a href=errata29.html#ptrace>January 21, 2002:
253: A race condition between the ptrace(2) and execve(2) system calls
254: allows an attacker to modify the memory contents of suid/sgid
255: processes which could lead to compromise of the super-user account.</a>
1.191 millert 256: <li><a href=errata29.html#sudo>January 17, 2002:
257: There is a security hole in sudo(8) that can be exploited
258: when the Postfix sendmail replacement is installed that may
259: allow an attacker on the local host to gain root privileges.</a>
1.189 millert 260: <li><a href=errata29.html#lpd2>November 28, 2001:
261: An attacker can trick a machine running the lpd daemon into
262: creating new files in the root directory from a machine with
263: remote line printer access.</a>
1.190 mpech 264: <li><a href=errata29.html#vi.recover>November 13, 2001:
265: The vi.recover script can be abused in such a way as
266: to cause arbitrary zero-length files to be removed.</a>
1.185 deraadt 267: <li><a href=errata29.html#uucp>September 11, 2001:
1.184 millert 268: A security hole exists in uuxqt(8) that may allow an
269: attacker to gain root privileges.</a>
1.185 deraadt 270: <li><a href=errata29.html#lpd>August 29, 2001:
1.183 millert 271: A security hole exists in lpd(8) that may allow an
272: attacker to gain root privileges if lpd is running.</a>
1.185 deraadt 273: <li><a href=errata29.html#sendmail2>August 21, 2001:
1.181 millert 274: A security hole exists in sendmail(8) that may allow an
275: attacker on the local host to gain root privileges.</a>
1.185 deraadt 276: <li><a href=errata29.html#nfs>July 30, 2001:
1.180 jason 277: A kernel buffer overflow in the NFS code can be used to execute
278: arbitrary code by users with mount privileges (only root by
1.181 millert 279: default).</a>
1.185 deraadt 280: <li><a href=errata29.html#kernexec>June 15, 2001:
1.178 aaron 281: A race condition in the kernel can lead to local root compromise.</a>
1.185 deraadt 282: <li><a href=errata29.html#sshcookie>June 12, 2001:
1.177 markus 283: sshd(8) allows users to delete arbitrary files named "cookies"
284: if X11 forwarding is enabled. X11 forwarding is disabled
285: by default.</a>
1.185 deraadt 286: <li><a href=errata29.html#fts>May 30, 2001:
1.176 millert 287: Programs using the fts routines can be tricked into changing
288: into the wrong directory.</a>
1.185 deraadt 289: <li><a href=errata29.html#sendmail>May 29, 2001:
1.174 millert 290: Sendmail signal handlers contain unsafe code,
291: leading to numerous race conditions.</a>
1.173 deraadt 292: </ul>
293:
294: <p>
295: <li>
1.152 deraadt 296: <a name=28></a>
297:
298: <h3><font color=#e00000>OpenBSD 2.8 Security Advisories</font></h3>
299: These are the OpenBSD 2.8 advisories -- all these problems are solved
1.154 millert 300: in <a href=anoncvs.html>OpenBSD current</a> and the
1.179 jufi 301: <a href=stable.html>patch branch</a>.
1.152 deraadt 302:
303: <p>
304: <ul>
1.184 millert 305: <li><a href=errata28.html#uucp>September 11, 2001:
306: A security hole exists in uuxqt(8) that may allow an
307: attacker to gain root privileges.</a>
1.183 millert 308: <li><a href=errata28.html#lpd>August 29, 2001:
309: A security hole exists in lpd(8) that may allow an
310: attacker to gain root privileges if lpd is running.</a>
1.181 millert 311: <li><a href=errata28.html#sendmail2>August 21, 2001:
312: A security hole exists in sendmail(8) that may allow an
313: attacker on the local host to gain root privileges.</a>
1.178 aaron 314: <li><a href=errata28.html#kernexec>June 15, 2001:
315: A race condition in the kernel can lead to local root compromise.</a>
1.176 millert 316: <li><a href=errata28.html#fts>May 30, 2001:
317: Programs using the fts routines can be tricked into changing
318: into the wrong directory.</a>
1.175 millert 319: <li><a href=errata28.html#sendmail>May 29, 2001:
320: Sendmail signal handlers contain unsafe code,
321: leading to numerous race conditions.</a>
1.173 deraadt 322: <li><a href=errata28.html#ipf_frag>Apr 23, 2001:
1.172 ericj 323: IPF contains a serious bug with its handling of fragment cacheing.</a>
1.173 deraadt 324: <li><a href=errata28.html#glob_limit>Apr 23, 2001:
1.172 ericj 325: ftpd(8) contains a potential DoS relating to glob(3).</a>
1.173 deraadt 326: <li><a href=errata28.html#glob>Apr 10, 2001:
1.170 ericj 327: The glob(3) library call contains multiple buffer overflows.</a>
1.173 deraadt 328: <li><a href=errata28.html#readline>Mar 18, 2001:
1.169 millert 329: The readline library creates history files with permissive modes based on the user's umask.</a>
1.173 deraadt 330: <li><a href=errata28.html#ipsec_ah>Mar 2, 2001:
1.167 ericj 331: Insufficient checks in the IPSEC AH IPv4 option handling code can lead to a buffer overrun in the kernel.</a>
1.173 deraadt 332: <li><a href=errata28.html#userldt>Mar 2, 2001:
1.168 horacio 333: The <b>USER_LDT</b> kernel option allows an attacker to gain access to privileged areas of kernel memory.</a>
1.173 deraadt 334: <li><a href=errata28.html#sudo>Feb 22, 2001:
1.171 millert 335: a non-exploitable buffer overflow was fixed in sudo(8).</a>
1.173 deraadt 336: <li><a href=errata28.html#named>Jan 29, 2001:
1.163 jason 337: merge named(8) with ISC BIND 4.9.8-REL, which fixes some buffer vulnerabilities.</a>
1.173 deraadt 338: <li><a href=errata28.html#rnd>Jan 22, 2001:
1.162 jason 339: rnd(4) did not use all of its input when written to.</a>
1.173 deraadt 340: <li><a href=errata28.html#xlock>Dec 22, 2000:
1.159 ericj 341: xlock(1)'s authentication was re-done to authenticate via a named pipe. (patch and new xlock binaries included).</a>
1.173 deraadt 342: <li><a href=errata28.html#procfs>Dec 18, 2000:
1.157 ericj 343: Procfs contains numerous overflows. Procfs is not used by default in OpenBSD. (patch included).</a>
1.173 deraadt 344: <li><a href=errata28.html#kerberos2>Dec 10, 2000:
1.156 deraadt 345: Another problem exists in KerberosIV libraries (patch included).</a>
1.173 deraadt 346: <li><a href=errata28.html#kerberos>Dec 7, 2000:
1.155 deraadt 347: A set of problems in KerberosIV exist (patch included).</a>
1.173 deraadt 348: <li><a href=errata28.html#ftpd>Dec 4, 2000:
1.154 millert 349: A single-byte buffer overflow exists in ftpd (patch included).</a>
1.152 deraadt 350: </ul>
351:
352: <p>
353: <li>
1.124 deraadt 354: <a name=27></a>
355:
356: <h3><font color=#e00000>OpenBSD 2.7 Security Advisories</font></h3>
357: These are the OpenBSD 2.7 advisories -- all these problems are solved
358: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
359: OpenBSD 2.6 advisories listed below are fixed in OpenBSD 2.7.
360:
361: <p>
362: <ul>
1.169 millert 363: <li><a href=errata27.html#readline>Mar 18, 2001:
364: The readline library creates history files with permissive modes based on the user's umask.</a>
365: <li><a href=errata27.html#sudo>Feb 22, 2001:
366: a buffer overflow was fixed in sudo(8).</a>
1.154 millert 367: <li><a href=errata27.html#ftpd>Dec 4, 2000:
368: A single-byte buffer overflow exists in ftpd (patch included).</a>
1.152 deraadt 369: <li><a href=errata27.html#sshforwarding>Nov 10, 2000:
370: Hostile servers can force OpenSSH clients to do agent or X11 forwarding.
371: (patch included)</a>
372: <li><a href=errata27.html#xtrans>Oct 26, 2000:
1.151 matthieu 373: X11 libraries have 2 potential overflows in xtrans code.
374: (patch included)</a>
1.152 deraadt 375: <li><a href=errata27.html#httpd>Oct 18, 2000:
1.150 beck 376: Apache mod_rewrite and mod_vhost_alias modules could expose files
377: on the server in certain configurations if used.
378: (patch included)</a>
1.164 deraadt 379: <li><a href=errata27.html#telnetd>Oct 10, 2000:
1.149 millert 380: The telnet daemon does not strip out the TERMINFO, TERMINFO_DIRS,
381: TERMPATH and TERMCAP environment variables as it should.
382: (patch included)</a>
1.152 deraadt 383: <li><a href=errata27.html#format_strings>Oct 6, 2000:
1.148 millert 384: There are printf-style format string bugs in several privileged
385: programs. (patch included)</a>
1.152 deraadt 386: <li><a href=errata27.html#curses>Oct 6, 2000:
1.147 millert 387: libcurses honored terminal descriptions in the $HOME/.terminfo
388: directory as well as in the TERMCAP environment variable for
389: setuid and setgid applications.
1.146 deraadt 390: (patch included)</a>
1.152 deraadt 391: <li><a href=errata27.html#talkd>Oct 6, 2000:
1.146 deraadt 392: A format string vulnerability exists in talkd(8).
393: (patch included)</a>
1.152 deraadt 394: <li><a href=errata27.html#pw_error>Oct 3, 2000:
1.145 aaron 395: A format string vulnerability exists in the pw_error() function of the
396: libutil library, yielding localhost root through chpass(1).
397: (patch included)</a>
1.152 deraadt 398: <li><a href=errata27.html#ipsec>Sep 18, 2000:
1.144 jason 399: Bad ESP/AH packets could cause a crash under certain conditions.
400: (patch included)</a>
1.152 deraadt 401: <li><a href=errata27.html#xlock>Aug 16, 2000:
1.141 deraadt 402: A format string vulnerability (localhost root) exists in xlock(1).
403: (patch included)</a>
1.152 deraadt 404: <li><a href=errata27.html#X11_libs>July 14, 2000:
1.139 deraadt 405: Various bugs found in X11 libraries have various side effects, almost
406: completely denial of service in OpenBSD.
407: (patch included)</a>
1.152 deraadt 408: <li><a href=errata27.html#ftpd>July 5, 2000:
1.136 deraadt 409: Just like pretty much all the other unix ftp daemons
410: on the planet, ftpd had a remote root hole in it.
411: Luckily, ftpd was not enabled by default.
1.137 deraadt 412: The problem exists if anonymous ftp is enabled.
1.136 deraadt 413: (patch included)</a>
1.152 deraadt 414: <li><a href=errata27.html#mopd>July 5, 2000:
1.136 deraadt 415: Mopd, very rarely used, contained some buffer overflows.
416: (patch included)</a>
1.152 deraadt 417: <li><a href=errata27.html#libedit>June 28, 2000:
1.135 deraadt 418: libedit would check for a <b>.editrc</b> file in the current
419: directory. Not known to be a real security issue, but a patch
420: is available anyways.
421: (patch included)</a>
1.152 deraadt 422: <li><a href=errata27.html#dhclient>June 24, 2000:
1.134 deraadt 423: A serious bug in dhclient(8) could allow strings from a
424: malicious dhcp server to be executed in the shell as root.
425: (patch included)</a>
1.152 deraadt 426: <li><a href=errata27.html#isakmpd>June 9, 2000:
1.133 deraadt 427: A serious bug in isakmpd(8) policy handling wherein
428: policy verification could be completely bypassed in isakmpd.
429: (patch included)</a>
1.152 deraadt 430: <li><a href=errata27.html#uselogin>June 6, 2000:
1.132 deraadt 431: The non-default flag UseLogin in <b>/etc/sshd_config</b> is broken,
432: should not be used, and results in security problems on
433: other operating systems.</a>
1.152 deraadt 434: <li><a href=errata27.html#bridge>May 26, 2000:
1.129 deraadt 435: The bridge(4) <i>learning</i> flag may be bypassed.
1.128 deraadt 436: (patch included)</a>
1.152 deraadt 437: <li><a href=errata27.html#ipf>May 25, 2000:
1.127 kjell 438: Improper use of ipf <i>keep-state</i> rules can result
439: in firewall rules being bypassed. (patch included)</a>
440:
1.124 deraadt 441: </ul>
442:
443: <p>
444: <li>
1.119 deraadt 445: <a name=26></a>
446:
447: <h3><font color=#e00000>OpenBSD 2.6 Security Advisories</font></h3>
448: These are the OpenBSD 2.6 advisories -- all these problems are solved
449: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
450: OpenBSD 2.5 advisories listed below are fixed in OpenBSD 2.6.
451:
452: <p>
453: <ul>
1.130 deraadt 454: <li><a href=errata26.html#semconfig>May 26, 2000:
455: SYSV semaphore support contained an undocumented system call
1.131 deraadt 456: which could wedge semaphore-using processes from exiting. (patch included)</a>
1.127 kjell 457: <li><a href=errata26.html#ipf>May 25, 2000:
458: Improper use of ipf <i>keep-state</i> rules can result
459: in firewall rules being bypassed. (patch included)</a>
1.126 deraadt 460: <li><a href=errata26.html#xlockmore>May 25, 2000:
1.125 deraadt 461: xlockmore has a bug which a localhost attacker can use to gain
462: access to the encrypted root password hash (which is normally
463: encoded using blowfish (see
464: <a href="http://www.openbsd.org/cgi-bin/man.cgi?query=crypt&sektion=3">
465: crypt(3)</a>)
466: (patch included).</a>
1.126 deraadt 467: <li><a href=errata26.html#procfs>Jan 20, 2000:
1.123 deraadt 468: Systems running with procfs enabled and mounted are
469: vulnerable to a very tricky exploit. procfs is not
470: mounted by default.
471: (patch included).</a>
1.190 mpech 472: <li><a href=errata26.html#sendmail>Dec 4, 1999:
473: Sendmail permitted any user to cause a aliases file wrap,
474: thus exposing the system to a race where the aliases file
475: did not exist.
1.119 deraadt 476: (patch included).</a>
1.190 mpech 477: <li><a href=errata26.html#poll>Dec 4, 1999:
478: Various bugs in poll(2) may cause a kernel crash.</a>
1.126 deraadt 479: <li><a href=errata26.html#sslUSA>Dec 2, 1999:
1.120 deraadt 480: A buffer overflow in the RSAREF code included in the
481: USA version of libssl, is possibly exploitable in
482: httpd, ssh, or isakmpd, if SSL/RSA features are enabled.
1.124 deraadt 483: (patch included).<br></a>
484: <strong>Update:</strong> Turns out that this was not exploitable
485: in any of the software included in OpenBSD 2.6.
1.190 mpech 486: <li><a href=errata26.html#ifmedia>Nov 9, 1999:
487: Any user could change interface media configurations, resulting in
488: a localhost denial of service attack.
1.121 deraadt 489: (patch included).</a>
1.119 deraadt 490: </ul>
491:
492: <p>
493: <li>
494:
1.93 deraadt 495: <a name=25></a>
1.106 deraadt 496:
1.110 deraadt 497: <h3><font color=#e00000>OpenBSD 2.5 Security Advisories</font></h3>
1.93 deraadt 498: These are the OpenBSD 2.5 advisories -- all these problems are solved
499: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
500: OpenBSD 2.4 advisories listed below are fixed in OpenBSD 2.5.
501:
1.96 deraadt 502: <p>
1.104 deraadt 503: <ul>
1.117 deraadt 504: <li><a href=errata25.html#cron>Aug 30, 1999:
1.103 deraadt 505: In cron(8), make sure argv[] is NULL terminated in the
506: fake popen() and run sendmail as the user, not as root.
507: (patch included).</a>
1.117 deraadt 508: <li><a href=errata25.html#miscfs>Aug 12, 1999: The procfs and fdescfs
1.101 deraadt 509: filesystems had an overrun in their handling of uio_offset
510: in their readdir() routines. (These filesystems are not
511: enabled by default). (patch included).</a>
1.117 deraadt 512: <li><a href=errata25.html#profil>Aug 9, 1999: Stop profiling (see profil(2))
1.100 deraadt 513: when we execve() a new process. (patch included).</a>
1.117 deraadt 514: <li><a href=errata25.html#ipsec_in_use>Aug 6, 1999: Packets that should have
1.98 deraadt 515: been handled by IPsec may be transmitted as cleartext.
516: PF_KEY SA expirations may leak kernel resources.
517: (patch included).</a>
1.117 deraadt 518: <li><a href=errata25.html#rc>Aug 5, 1999: In /etc/rc, use mktemp(1) for
1.97 deraadt 519: motd re-writing and change the find(1) to use -execdir
520: (patch included).</a>
1.117 deraadt 521: <li><a href=errata25.html#chflags>Jul 30, 1999: Do not permit regular
1.95 deraadt 522: users to chflags(2) or fchflags(2) on character or block devices
523: which they may currently be the owner of (patch included).</a>
1.117 deraadt 524: <li><a href=errata25.html#nroff>Jul 27, 1999: Cause groff(1) to be invoked
1.95 deraadt 525: with the -S flag, when called by nroff(1) (patch included).</a>
1.93 deraadt 526: </ul>
527:
1.106 deraadt 528: <p>
529: <li>
1.75 deraadt 530: <a name=24></a>
1.110 deraadt 531: <h3><font color=#e00000>OpenBSD 2.4 Security Advisories</font></h3>
1.75 deraadt 532: These are the OpenBSD 2.4 advisories -- all these problems are solved
533: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
534: OpenBSD 2.3 advisories listed below are fixed in OpenBSD 2.4.
535:
1.96 deraadt 536: <p>
1.75 deraadt 537: <ul>
1.92 deraadt 538: <li><a href=errata24.html#poll>Mar 22, 1999: The nfds argument for poll(2) needs
1.91 deraadt 539: to be constrained, to avoid kvm starvation (patch included).</a>
1.92 deraadt 540: <li><a href=errata24.html#tss>Mar 21, 1999: A change in TSS handling stops
1.91 deraadt 541: another kernel crash case caused by the <strong>crashme</strong>
542: program (patch included).</a>
1.92 deraadt 543: <li><a href=errata24.html#nlink>Feb 25, 1999: An unbounded increment on the
1.90 deraadt 544: nlink value in FFS and EXT2FS filesystems can cause a system crash.
1.89 deraadt 545: (patch included).</a>
1.92 deraadt 546: <li><a href=errata24.html#ping>Feb 23, 1999: Yet another buffer overflow
1.88 deraadt 547: existed in ping(8). (patch included).</a>
1.92 deraadt 548: <li><a href=errata24.html#ipqrace>Feb 19, 1999: ipintr() had a race in use of
1.87 deraadt 549: the ipq, which could permit an attacker to cause a crash.
550: (patch included).</a>
1.92 deraadt 551: <li><a href=errata24.html#accept>Feb 17, 1999: A race condition in the
1.86 deraadt 552: kernel between accept(2) and select(2) could permit an attacker
553: to hang sockets from remote.
554: (patch included).</a>
1.92 deraadt 555: <li><a href=errata24.html#maxqueue>Feb 17, 1999: IP fragment assembly can
1.85 deraadt 556: bog the machine excessively and cause problems.
557: (patch included).</a>
1.92 deraadt 558: <li><a href=errata24.html#trctrap>Feb 12, 1999: i386 T_TRCTRAP handling and
1.84 deraadt 559: DDB interacted to possibly cause a crash.
560: (patch included).</a>
1.92 deraadt 561: <li><a href=errata24.html#rst>Feb 11, 1999: TCP/IP RST handling was sloppy.
1.83 deraadt 562: (patch included).</a>
1.92 deraadt 563: <li><a href=errata24.html#bootpd>Nov 27, 1998: There is a remotely exploitable
1.81 deraadt 564: problem in bootpd(8). (patch included).</a>
1.92 deraadt 565: <li><a href=errata24.html#termcap>Nov 19, 1998: There is a possibly locally
1.82 deraadt 566: exploitable problem relating to environment variables in termcap
567: and curses. (patch included).</a>
1.92 deraadt 568: <li><a href=errata24.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
1.78 deraadt 569: bug in the TCP decoding kernel. (patch included).</a>
1.75 deraadt 570: </ul>
571:
1.106 deraadt 572: <p>
573: <li>
1.58 deraadt 574: <a name=23></a>
1.110 deraadt 575: <h3><font color=#e00000>OpenBSD 2.3 Security Advisories</font></h3>
1.73 deraadt 576: These are the OpenBSD 2.3 advisories -- all these problems are solved
577: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
578: OpenBSD 2.2 advisories listed below are fixed in OpenBSD 2.3.
1.53 matthieu 579:
1.96 deraadt 580: <p>
1.53 matthieu 581: <ul>
1.81 deraadt 582: <li><a href=errata23.html#bootpd>Nov 27, 1998: There is a remotely exploitable
583: problem in bootpd(8). (patch included).</a>
1.78 deraadt 584: <li><a href=errata23.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
585: bug in the TCP decoding kernel. (patch included).</a>
1.190 mpech 586: <li><a href=errata23.html#resolver>August 31, 1998: A benign looking resolver
587: buffer overflow bug was re-introduced accidentally (patches included).</a>
588: <li><a href=errata23.html#chpass>Aug 2, 1998:
589: chpass(1) has a file descriptor leak which allows an
590: attacker to modify /etc/master.passwd.</a>
591: <li><a href=errata23.html#inetd>July 15, 1998: Inetd had a file descriptor leak.</a>
1.76 aaron 592: <li><a href=errata23.html#fdalloc>Jul 2, 1998: setuid and setgid processes
1.72 deraadt 593: should not be executed with fd slots 0, 1, or 2 free.
594: (patch included).</a>
1.76 aaron 595: <li><a href=errata23.html#xlib>June 6, 1998: Further problems with the X
1.71 deraadt 596: libraries (patches included).</a>
1.76 aaron 597: <li><a href=errata23.html#kill>May 17, 1998: kill(2) of setuid/setgid target
1.66 deraadt 598: processes too permissive (4th revision patch included).</a>
1.76 aaron 599: <li><a href=errata23.html#immutable>May 11, 1998: mmap() permits partial bypassing
1.60 deraadt 600: of immutable and append-only file flags. (patch included).</a>
1.190 mpech 601: <li><a href=errata23.html#ipsec>May 5, 1998: Incorrect handling of IPSEC packets
602: if IPSEC is enabled (patch included).</a>
1.76 aaron 603: <li><a href=errata23.html#xterm-xaw>May 1, 1998: Buffer overflow in xterm and Xaw
1.58 deraadt 604: (CERT advisory VB-98.04) (patch included).</a>
1.53 matthieu 605: </ul>
1.9 deraadt 606:
1.106 deraadt 607: <p>
608: <li>
1.58 deraadt 609: <a name=22></a>
1.110 deraadt 610: <h3><font color=#e00000>OpenBSD 2.2 Security Advisories</font></h3>
1.45 deraadt 611: These are the OpenBSD 2.2 advisories. All these problems are solved
1.55 deraadt 612: in <a href=23.html>OpenBSD 2.3</a>. Some of these problems
1.45 deraadt 613: still exist in other operating systems. (The supplied patches are for
614: OpenBSD 2.2; they may or may not work on OpenBSD 2.1).
1.9 deraadt 615:
1.96 deraadt 616: <p>
1.9 deraadt 617: <ul>
1.72 deraadt 618: <li><a href=errata22.html#ipsec>May 5, 1998: Incorrect handling of IPSEC
619: packets if IPSEC is enabled (patch included).</a>
620: <li><a href=errata22.html#xterm-xaw>May 1, 1998: Buffer overflow in xterm
621: and Xaw (CERT advisory VB-98.04) (patch included).</a>
622: <li><a href=errata22.html#uucpd>Apr 22, 1998: Buffer overflow in uucpd
623: (patch included).</a>
624: <li><a href=errata22.html#rmjob>Apr 22, 1998: Buffer mismanagement in lprm
625: (patch included).</a>
626: <li><a href=errata22.html#ping>Mar 31, 1998: Overflow in ping -R (patch included).</a>
627: <li><a href=errata22.html#named>Mar 30, 1998: Overflow in named fake-iquery
1.59 deraadt 628: (patch included).</a>
1.72 deraadt 629: <li><a href=errata22.html#mountd>Mar 2, 1998: Accidental NFS filesystem
630: export (patch included).</a>
1.112 philen 631: <li><a href="advisories/mmap.txt">Feb 26, 1998: Read-write mmap() flaw.</a>
1.72 deraadt 632: Revision 3 of the patch is available <a href=errata22.html#mmap>here</a>
1.112 philen 633: <li><a href="advisories/sourceroute.txt">Feb 19, 1998: Sourcerouted Packet
1.59 deraadt 634: Acceptance.</a>
1.50 deraadt 635: A patch is available <a href=errata22.html#sourceroute>here</a>.
1.122 rohee 636: <li><a href=errata22.html#ruserok>Feb 13, 1998: Setuid coredump & Ruserok()
1.72 deraadt 637: flaw (patch included).</a>
638: <li><a href=errata22.html#ldso>Feb 9, 1998: MIPS ld.so flaw (patch included).</a>
1.1 deraadt 639: </ul>
640:
1.106 deraadt 641: <p>
642: <li>
1.58 deraadt 643: <a name=21></a>
1.110 deraadt 644: <h3><font color=#e00000>OpenBSD 2.1 Security Advisories</font></h3>
1.52 deraadt 645: These are the OpenBSD 2.1 advisories. All these problems are solved
646: in <a href=22.html>OpenBSD 2.2</a>. Some of these problems still
647: exist in other operating systems. (If you are running OpenBSD 2.1, we
648: would strongly recommend an upgrade to the newest release, as this
649: patch list only attempts at fixing the most important security
650: problems. In particular, OpenBSD 2.2 fixes numerous localhost
651: security problems. Many of those problems were solved in ways which
652: make it hard for us to provide patches).
653:
1.96 deraadt 654: <p>
1.52 deraadt 655: <ul>
1.112 philen 656: <li><a href="advisories/signals.txt">Sep 15, 1997: Deviant Signals (patch included)</a>
657: <li><a href="advisories/rfork.txt">Aug 2, 1997: Rfork() system call flaw
1.59 deraadt 658: (patch included)</a>
1.112 philen 659: <li><a href="advisories/procfs.txt">Jun 24, 1997: Procfs flaws (patch included)</a>
1.52 deraadt 660: </ul>
1.51 deraadt 661:
1.106 deraadt 662: <p>
663: <li>
664: <a name=20></a>
1.110 deraadt 665: <h3><font color=#e00000>OpenBSD 2.0 Security Advisories</font></h3>
1.99 deraadt 666: These are the OpenBSD 2.0 advisories. All these problems are solved
667: in <a href=21.html>OpenBSD 2.1</a>. Some of these problems still
668: exist in other operating systems. (If you are running OpenBSD 2.0, we
669: commend you for being there back in the old days!, but you're really
670: missing out if you don't install a new version!)
671:
672: <p>
673: <ul>
1.112 philen 674: <li><a href="advisories/res_random.txt">April 22, 1997: Predictable IDs in the
1.99 deraadt 675: resolver (patch included)</a>
676: <li>Many others... if people can hunt them down, please let me know
677: and we'll put them up here.
678: </ul>
679:
1.106 deraadt 680: </dl>
1.51 deraadt 681: <p>
1.106 deraadt 682:
683: <a name=watching></a>
1.110 deraadt 684: <li><h3><font color=#e00000>Watching our Changes</font></h3><p>
1.106 deraadt 685:
1.21 deraadt 686: Since we take a proactive stance with security, we are continually
687: finding and fixing new security problems. Not all of these problems
1.80 espie 688: get widely reported because (as stated earlier) many of them are not
1.45 deraadt 689: confirmed to be exploitable; many simple bugs we fix do turn out to
690: have security consequences we could not predict. We do not have the
691: time resources to make these changes available in the above format.<p>
1.21 deraadt 692:
693: Thus there are usually minor security fixes in the current source code
694: beyond the previous major OpenBSD release. We make a limited
1.45 deraadt 695: guarantee that these problems are of minimal impact and unproven
1.44 ian 696: exploitability. If we discover that a problem definitely matters for
1.45 deraadt 697: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21 deraadt 698:
1.45 deraadt 699: People who are really concerned with security can do a number of
700: things:<p>
1.21 deraadt 701:
702: <ul>
703: <li>If you understand security issues, watch our
1.27 deraadt 704: <a href=mail.html>source-changes mailing list</a> and keep an
1.23 deraadt 705: eye out for things which appear security related. Since
1.21 deraadt 706: exploitability is not proven for many of the fixes we make,
707: do not expect the relevant commit message to say "SECURITY FIX!".
708: If a problem is proven and serious, a patch will be available
709: here very shortly after.
1.161 horacio 710: <li>In addition to source changes, you can watch our <a href="mail.html">
1.160 ericj 711: security-announce mailing list</a> which will notify you for every
1.186 ian 712: security related item that the OpenBSD team deems as a possible threat,
1.160 ericj 713: and instruct you on how to patch the problem.
1.21 deraadt 714: <li>Track our current source code tree, and teach yourself how to do a
1.29 deraadt 715: complete system build from time to time (read /usr/src/Makefile
716: carefully). Users can make the assumption that the current
717: source tree always has stronger security than the previous release.
1.45 deraadt 718: However, building your own system from source code is not trivial;
719: it is nearly 300MB of source code, and problems do occur as we
720: transition between major releases.
1.115 ericj 721: <li>Install a binary snapshot for your
1.80 espie 722: architecture, which are made available fairly often. For
1.29 deraadt 723: instance, an i386 snapshot is typically made available weekly.
1.21 deraadt 724: </ul>
725:
1.9 deraadt 726: <p>
1.153 jufi 727: <a name=reporting></a>
1.110 deraadt 728: <li><h3><font color=#e00000>Reporting problems</font></h3><p>
1.3 deraadt 729:
1.5 deraadt 730: <p> If you find a new security problem, you can mail it to
1.6 deraadt 731: <a href=mailto:deraadt@openbsd.org>deraadt@openbsd.org</a>.
1.7 deraadt 732: <br>
1.5 deraadt 733: If you wish to PGP encode it (but please only do so if privacy is very
1.112 philen 734: urgent, since it is inconvenient) use this <a href="advisories/pgpkey.txt">pgp key</a>.
1.5 deraadt 735:
1.107 deraadt 736: <p>
737: <a name=papers></a>
1.110 deraadt 738: <li><h3><font color=#e00000>Further Reading</font></h3><p>
1.107 deraadt 739:
740: A number of papers have been written by OpenBSD team members, about security
741: related changes they have done in OpenBSD. The postscript versions of these
1.108 deraadt 742: documents are available as follows.<p>
1.107 deraadt 743:
744: <ul>
1.113 deraadt 745: <li>A Future-Adaptable Password Scheme.<br>
1.118 deraadt 746: <a href=events.html#usenix99>Usenix 1999</a>,
1.153 jufi 747: by <a href=mailto:provos@openbsd.org>Niels Provos</a>,
1.113 deraadt 748: <a href=mailto:dm@openbsd.org>David Mazieres</a>.<br>
1.107 deraadt 749: <a href=papers/bcrypt-paper.ps>paper</a> and
750: <a href=papers/bcrypt-slides.ps>slides</a>.
1.113 deraadt 751: <p>
752: <li>Cryptography in OpenBSD: An Overview.<br>
1.118 deraadt 753: <a href=events.html#usenix99>Usenix 1999</a>,
1.113 deraadt 754: by <a href=mailto:deraadt@openbsd.org>Theo de Raadt</a>,
755: <a href=mailto:niklas@openbsd.org>Niklas Hallqvist</a>,
756: <a href=mailto:art@openbsd.org>Artur Grabowski</a>,
757: <a href=mailto:angelos@openbsd.org>Angelos D. Keromytis</a>,
758: <a href=mailto:provos@openbsd.org>Niels Provos</a>.<br>
1.107 deraadt 759: <a href=papers/crypt-paper.ps>paper</a> and
760: <a href=papers/crypt-slides.ps>slides</a>.
1.113 deraadt 761: <p>
762: <li>strlcpy and strlcat -- consistent, safe, string copy and concatenation.<br>
1.118 deraadt 763: <a href=events.html#usenix99>Usenix 1999</a>,
1.113 deraadt 764: by <a href=mailto:millert@openbsd.org>Todd C. Miller</a>,
765: <a href=mailto:deraadt@openbsd.org>Theo de Raadt</a>.<br>
1.109 deraadt 766: <a href=papers/strlcpy-paper.ps>paper</a> and
767: <a href=papers/strlcpy-slides.ps>slides</a>.
1.113 deraadt 768: <p>
1.118 deraadt 769: <li>Dealing with Public Ethernet Jacks-Switches, Gateways, and Authentication.<br>
770: <a href=events.html#lisa99>LISA 1999</a>,
771: by <a href=mailto:beck@openbsd.org>Bob Beck</a>.<br>
772: <a href=papers/authgw-paper.ps>paper</a> and
773: <a href=papers/authgw-slides.ps>slides</a>.
774: <p>
1.153 jufi 775: <li>Encrypting Virtual Memory<br>
1.142 deraadt 776: <a href=events.html#sec2000>Usenix Security 2000</a>,
777: <a href=mailto:provos@openbsd.org>Niels Provos</a>.<br>
1.143 provos 778: <a href=papers/swapencrypt.ps>paper</a> and
779: <a href=papers/swapencrypt-slides.ps>slides</a>.
1.142 deraadt 780: <p>
1.107 deraadt 781: </ul>
782:
1.106 deraadt 783: </dl>
784:
1.2 deraadt 785: <hr>
1.68 pauls 786: <a href=index.html><img height=24 width=24 src=back.gif border=0 alt=OpenBSD></a>
1.24 deraadt 787: <a href=mailto:www@openbsd.org>www@openbsd.org</a>
788: <br>
1.201 ! millert 789: <small>$OpenBSD: security.html,v 1.200 2002/03/14 05:38:54 millert Exp $</small>
1.1 deraadt 790:
1.24 deraadt 791: </body>
792: </html>
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