Annotation of www/security.html, Revision 1.102
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1.20 deraadt 4: <title>OpenBSD Security</title>
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14:
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1.1 deraadt 16:
1.56 deraadt 17: <hr>
18: <a href=#21>For 2.1 security advisories, please refer here</a>.<br>
19: <a href=#22>For 2.2 security advisories, please refer here</a>.<br>
20: <a href=#23>For 2.3 security advisories, please refer here</a>.<br>
1.75 deraadt 21: <a href=#24>For 2.4 security advisories, please refer here</a>.<br>
1.93 deraadt 22: <a href=#25>For 2.5 security advisories, please refer here</a>.<br>
1.56 deraadt 23: <hr>
24:
1.2 deraadt 25: <p>
1.12 deraadt 26: <h3><font color=#e00000><strong>OpenBSD Security Views</strong></font></h3>
1.22 deraadt 27:
1.14 deraadt 28: OpenBSD believes in strong security. Our aspiration is to be NUMBER
1.22 deraadt 29: ONE in the industry for security (if we are not already there). Our
30: open software development model permits us to take a more
31: uncompromising view towards increased security than Sun, SGI, IBM, HP,
32: or other vendors are able to. We can make changes the vendors would
1.27 deraadt 33: not make. Also, since OpenBSD is exported with <a href=crypto.html>
1.45 deraadt 34: cryptography</a>, we are able to take cryptographic approaches towards
35: fixing security problems.<p>
1.18 deraadt 36:
1.45 deraadt 37: Like many readers of the
1.102 ! deraadt 38: <a href=http://www.securityfocus.com/bugtraq/archive>
1.18 deraadt 39: BUGTRAQ mailing list</a>,
1.45 deraadt 40: we believe in full disclosure of security problems. Security
41: information moves very fast in cracker circles. On the other hand,
42: our experience is that coding and releasing of proper security fixes
43: typically requires about an hour of work -- very fast fix turnaround
44: is possible. Thus we think that full disclosure helps the people who
1.22 deraadt 45: really care about security.<p>
1.15 deraadt 46:
1.12 deraadt 47: Our security auditing team typically has between six and twelve
1.45 deraadt 48: members who continue to search for and fix new security holes. We
49: have been auditing since the summer of 1996. The process we follow to
50: increase security is simply a comprehensive file-by-file analysis of
51: every critical software component. Flaws have been found in just
52: about every area of the system. Entire new classes of security
1.80 espie 53: problems have been found during our audit, and often source code
1.45 deraadt 54: which had been audited earlier needs re-auditing with these new flaws
55: in mind. Code often gets audited multiple times, and by multiple
56: people with different auditing skills.<p>
1.12 deraadt 57:
1.94 deraadt 58: Some members of our security auditing team worked for Secure Networks,
59: the company that made the industry's premier network security scanning
60: software package Ballista (Secure Networks got purchased by Network
61: Associates, Ballista got renamed to Cybercop Scanner, and well...)
62: That company did a lot of security research, and thus fit in well
1.45 deraadt 63: with the OpenBSD stance. OpenBSD passes Ballista's tests with flying
64: colours.<p>
1.31 deraadt 65:
1.34 deraadt 66: Another facet of our security auditing process is its proactiveness.
1.45 deraadt 67: In most cases we have found that the determination of exploitability
68: is not an issue. During our ongoing auditing process we find many
69: bugs, and endeavor to fix them even though exploitability is not
70: proven. We fix the bug, and we move on to find other bugs to fix. We
71: have fixed many simple and obvious careless programming errors in code
72: and only months later discovered that the problems were in fact
73: exploitable. (Or, more likely someone on
1.102 ! deraadt 74: <a href=http://www.securityfocus.com/bugtraq/archive>BUGTRAQ</a>
1.45 deraadt 75: would report that other operating systems were vulnerable to a `newly
76: discovered problem', and then it would be discovered that OpenBSD had
77: been fixed in a previous release). In other cases we have been saved
78: from full exploitability of complex step-by-step attacks because we
79: had fixed one of the intermediate steps. An example of where we
1.94 deraadt 80: managed such a success is the lpd advisory that Secure Networks put out.
81: <p>
1.29 deraadt 82:
1.45 deraadt 83: Our proactive auditing process has really paid off. Statements like
1.35 deraadt 84: ``This problem was fixed in OpenBSD about 6 months ago'' have become
1.45 deraadt 85: commonplace in security forums like
1.102 ! deraadt 86: <a href=http://www.securityfocus.com/bugtraq/archive>BUGTRAQ</a>.<p>
1.35 deraadt 87:
1.45 deraadt 88: The most intense part of our security auditing happened immediately
1.80 espie 89: before the OpenBSD 2.0 release and during the 2.0->2.1 transition,
1.45 deraadt 90: over the last third of 1996 and first half of 1997. Thousands (yes,
91: thousands) of security issues were fixed rapidly over this year-long
92: period; bugs like the standard buffer overflows, protocol
93: implementation weaknesses, information gathering, and filesystem
94: races. Hence most of the security problems that we encountered were
95: fixed before our 2.1 release, and then a far smaller number needed
96: fixing for our 2.2 release. We do not find as many problems anymore,
97: it is simply a case of diminishing returns. Recently the security
98: problems we find and fix tend to be significantly more obscure or
99: complicated. Still we will persist for a number of reasons:<p>
1.36 deraadt 100:
1.35 deraadt 101: <ul>
1.45 deraadt 102: <li>Occasionally we find a simple problem we missed earlier. Doh!
1.35 deraadt 103: <li>Security is like an arms race; the best attackers will continue
1.45 deraadt 104: to search for more complicated exploits, so we will too.
105: <li>Finding and fixing subtle flaws in complicated software is
106: a lot of fun.
1.35 deraadt 107: </ul>
1.15 deraadt 108:
1.14 deraadt 109: The auditing process is not over yet, and as you can see we continue
1.28 deraadt 110: to find and fix new security flaws.<p>
1.12 deraadt 111:
1.93 deraadt 112: <a name=25></a>
113: <p>
114: <h3><font color=#e00000><strong>OpenBSD 2.5 Security Advisories</strong></font></h3>
115: These are the OpenBSD 2.5 advisories -- all these problems are solved
116: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
117: OpenBSD 2.4 advisories listed below are fixed in OpenBSD 2.5.
118:
1.96 deraadt 119: <p>
1.101 deraadt 120: <ul><a href=errata.html#miscfs>Aug 12, 1999: The procfs and fdescfs
121: filesystems had an overrun in their handling of uio_offset
122: in their readdir() routines. (These filesystems are not
123: enabled by default). (patch included).</a>
1.100 deraadt 124: <li><a href=errata.html#profil>Aug 9, 1999: Stop profiling (see profil(2))
125: when we execve() a new process. (patch included).</a>
1.98 deraadt 126: <li><a href=errata.html#rc>Aug 6, 1999: Packets that should have
127: been handled by IPsec may be transmitted as cleartext.
128: PF_KEY SA expirations may leak kernel resources.
129: (patch included).</a>
1.97 deraadt 130: <li><a href=errata.html#rc>Aug 5, 1999: In /etc/rc, use mktemp(1) for
131: motd re-writing and change the find(1) to use -execdir
132: (patch included).</a>
1.95 deraadt 133: <li><a href=errata.html#chflags>Jul 30, 1999: Do not permit regular
134: users to chflags(2) or fchflags(2) on character or block devices
135: which they may currently be the owner of (patch included).</a>
136: <li><a href=errata.html#nroff>Jul 27, 1999: Cause groff(1) to be invoked
137: with the -S flag, when called by nroff(1) (patch included).</a>
1.93 deraadt 138: </ul>
139:
1.75 deraadt 140: <a name=24></a>
141: <p>
142: <h3><font color=#e00000><strong>OpenBSD 2.4 Security Advisories</strong></font></h3>
143: These are the OpenBSD 2.4 advisories -- all these problems are solved
144: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
145: OpenBSD 2.3 advisories listed below are fixed in OpenBSD 2.4.
146:
1.96 deraadt 147: <p>
1.75 deraadt 148: <ul>
1.92 deraadt 149: <li><a href=errata24.html#poll>Mar 22, 1999: The nfds argument for poll(2) needs
1.91 deraadt 150: to be constrained, to avoid kvm starvation (patch included).</a>
1.92 deraadt 151: <li><a href=errata24.html#tss>Mar 21, 1999: A change in TSS handling stops
1.91 deraadt 152: another kernel crash case caused by the <strong>crashme</strong>
153: program (patch included).</a>
1.92 deraadt 154: <li><a href=errata24.html#nlink>Feb 25, 1999: An unbounded increment on the
1.90 deraadt 155: nlink value in FFS and EXT2FS filesystems can cause a system crash.
1.89 deraadt 156: (patch included).</a>
1.92 deraadt 157: <li><a href=errata24.html#ping>Feb 23, 1999: Yet another buffer overflow
1.88 deraadt 158: existed in ping(8). (patch included).</a>
1.92 deraadt 159: <li><a href=errata24.html#ipqrace>Feb 19, 1999: ipintr() had a race in use of
1.87 deraadt 160: the ipq, which could permit an attacker to cause a crash.
161: (patch included).</a>
1.92 deraadt 162: <li><a href=errata24.html#accept>Feb 17, 1999: A race condition in the
1.86 deraadt 163: kernel between accept(2) and select(2) could permit an attacker
164: to hang sockets from remote.
165: (patch included).</a>
1.92 deraadt 166: <li><a href=errata24.html#maxqueue>Feb 17, 1999: IP fragment assembly can
1.85 deraadt 167: bog the machine excessively and cause problems.
168: (patch included).</a>
1.92 deraadt 169: <li><a href=errata24.html#trctrap>Feb 12, 1999: i386 T_TRCTRAP handling and
1.84 deraadt 170: DDB interacted to possibly cause a crash.
171: (patch included).</a>
1.92 deraadt 172: <li><a href=errata24.html#rst>Feb 11, 1999: TCP/IP RST handling was sloppy.
1.83 deraadt 173: (patch included).</a>
1.92 deraadt 174: <li><a href=errata24.html#bootpd>Nov 27, 1998: There is a remotely exploitable
1.81 deraadt 175: problem in bootpd(8). (patch included).</a>
1.92 deraadt 176: <li><a href=errata24.html#termcap>Nov 19, 1998: There is a possibly locally
1.82 deraadt 177: exploitable problem relating to environment variables in termcap
178: and curses. (patch included).</a>
1.92 deraadt 179: <li><a href=errata24.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
1.78 deraadt 180: bug in the TCP decoding kernel. (patch included).</a>
1.75 deraadt 181: </ul>
182:
1.58 deraadt 183: <a name=23></a>
1.12 deraadt 184: <p>
1.52 deraadt 185: <h3><font color=#e00000><strong>OpenBSD 2.3 Security Advisories</strong></font></h3>
1.73 deraadt 186: These are the OpenBSD 2.3 advisories -- all these problems are solved
187: in <a href=anoncvs.html>OpenBSD current</a>. Obviously, all the
188: OpenBSD 2.2 advisories listed below are fixed in OpenBSD 2.3.
1.53 matthieu 189:
1.96 deraadt 190: <p>
1.53 matthieu 191: <ul>
1.81 deraadt 192: <li><a href=errata23.html#bootpd>Nov 27, 1998: There is a remotely exploitable
193: problem in bootpd(8). (patch included).</a>
1.78 deraadt 194: <li><a href=errata23.html#tcpfix>Nov 13, 1998: There is a remote machine lockup
195: bug in the TCP decoding kernel. (patch included).</a>
1.76 aaron 196: <li><a href=errata23.html#fdalloc>Jul 2, 1998: setuid and setgid processes
1.72 deraadt 197: should not be executed with fd slots 0, 1, or 2 free.
198: (patch included).</a>
1.79 deraadt 199: <li><a href=errata23.html#resolver>August 31, 1998: A benign looking resolver buffer overflow bug was re-introduced accidentally (patches included).</a>
1.76 aaron 200: <li><a href=errata23.html#xlib>June 6, 1998: Further problems with the X
1.71 deraadt 201: libraries (patches included).</a>
1.76 aaron 202: <li><a href=errata23.html#pctr>June 4, 1998: on non-Intel i386 machines, any user
1.72 deraadt 203: can use pctr(4) to crash the machine.</a>
1.76 aaron 204: <li><a href=errata23.html#kill>May 17, 1998: kill(2) of setuid/setgid target
1.66 deraadt 205: processes too permissive (4th revision patch included).</a>
1.76 aaron 206: <li><a href=errata23.html#immutable>May 11, 1998: mmap() permits partial bypassing
1.60 deraadt 207: of immutable and append-only file flags. (patch included).</a>
1.76 aaron 208: <li><a href=errata23.html#xterm-xaw>May 1, 1998: Buffer overflow in xterm and Xaw
1.58 deraadt 209: (CERT advisory VB-98.04) (patch included).</a>
1.76 aaron 210: <li><a href=errata23.html#ipsec>May 5, 1998: Incorrect handling of IPSEC packets
1.59 deraadt 211: if IPSEC is enabled (patch included).</a>
1.53 matthieu 212: </ul>
1.9 deraadt 213:
1.58 deraadt 214: <a name=22></a>
1.9 deraadt 215: <p>
1.12 deraadt 216: <h3><font color=#e00000><strong>OpenBSD 2.2 Security Advisories</strong></font></h3>
1.45 deraadt 217: These are the OpenBSD 2.2 advisories. All these problems are solved
1.55 deraadt 218: in <a href=23.html>OpenBSD 2.3</a>. Some of these problems
1.45 deraadt 219: still exist in other operating systems. (The supplied patches are for
220: OpenBSD 2.2; they may or may not work on OpenBSD 2.1).
1.9 deraadt 221:
1.96 deraadt 222: <p>
1.9 deraadt 223: <ul>
1.72 deraadt 224: <li><a href=errata22.html#ipsec>May 5, 1998: Incorrect handling of IPSEC
225: packets if IPSEC is enabled (patch included).</a>
226: <li><a href=errata22.html#xterm-xaw>May 1, 1998: Buffer overflow in xterm
227: and Xaw (CERT advisory VB-98.04) (patch included).</a>
228: <li><a href=errata22.html#uucpd>Apr 22, 1998: Buffer overflow in uucpd
229: (patch included).</a>
230: <li><a href=errata22.html#rmjob>Apr 22, 1998: Buffer mismanagement in lprm
231: (patch included).</a>
232: <li><a href=errata22.html#ping>Mar 31, 1998: Overflow in ping -R (patch included).</a>
233: <li><a href=errata22.html#named>Mar 30, 1998: Overflow in named fake-iquery
1.59 deraadt 234: (patch included).</a>
1.72 deraadt 235: <li><a href=errata22.html#mountd>Mar 2, 1998: Accidental NFS filesystem
236: export (patch included).</a>
237: <li><a href=advisories/mmap>Feb 26, 1998: Read-write mmap() flaw.</a>
238: Revision 3 of the patch is available <a href=errata22.html#mmap>here</a>
1.59 deraadt 239: <li><a href=advisories/sourceroute>Feb 19, 1998: Sourcerouted Packet
240: Acceptance.</a>
1.50 deraadt 241: A patch is available <a href=errata22.html#sourceroute>here</a>.
1.72 deraadt 242: <li><a href=errata22.html#ruserok>Feb 13, 1998: Setuid coredump & Ruserok()
243: flaw (patch included).</a>
244: <li><a href=errata22.html#ldso>Feb 9, 1998: MIPS ld.so flaw (patch included).</a>
245: <li><a href=errata22.html#f00f>Dec 10, 1997: Intel P5 f00f lockup
1.59 deraadt 246: (patch included).</a>
1.1 deraadt 247: </ul>
248:
1.58 deraadt 249: <a name=21></a>
1.21 deraadt 250: <p>
1.52 deraadt 251: <h3><font color=#e00000><strong>OpenBSD 2.1 Security Advisories</strong></font></h3>
252: These are the OpenBSD 2.1 advisories. All these problems are solved
253: in <a href=22.html>OpenBSD 2.2</a>. Some of these problems still
254: exist in other operating systems. (If you are running OpenBSD 2.1, we
255: would strongly recommend an upgrade to the newest release, as this
256: patch list only attempts at fixing the most important security
257: problems. In particular, OpenBSD 2.2 fixes numerous localhost
258: security problems. Many of those problems were solved in ways which
259: make it hard for us to provide patches).
260:
1.96 deraadt 261: <p>
1.52 deraadt 262: <ul>
1.72 deraadt 263: <li><a href=advisories/signals>Sep 15, 1997: Deviant Signals (patch included)</a>
1.59 deraadt 264: <li><a href=advisories/rfork>Aug 2, 1997: Rfork() system call flaw
265: (patch included)</a>
266: <li><a href=advisories/procfs>Jun 24, 1997: Procfs flaws (patch included)</a>
1.52 deraadt 267: </ul>
1.51 deraadt 268:
1.99 deraadt 269: <h3><font color=#e00000><strong>OpenBSD 2.0 Security Advisories</strong></font></h3>
270: These are the OpenBSD 2.0 advisories. All these problems are solved
271: in <a href=21.html>OpenBSD 2.1</a>. Some of these problems still
272: exist in other operating systems. (If you are running OpenBSD 2.0, we
273: commend you for being there back in the old days!, but you're really
274: missing out if you don't install a new version!)
275:
276: <p>
277: <ul>
278: <li><a href=advisories/res_random>April 22, 1997: Predictable IDs in the
279: resolver (patch included)</a>
280: <li>Many others... if people can hunt them down, please let me know
281: and we'll put them up here.
282: </ul>
283:
1.51 deraadt 284: <p>
1.21 deraadt 285: <h3><font color=#e00000><strong>Watching our Security Changes</strong></font></h3>
286: Since we take a proactive stance with security, we are continually
287: finding and fixing new security problems. Not all of these problems
1.80 espie 288: get widely reported because (as stated earlier) many of them are not
1.45 deraadt 289: confirmed to be exploitable; many simple bugs we fix do turn out to
290: have security consequences we could not predict. We do not have the
291: time resources to make these changes available in the above format.<p>
1.21 deraadt 292:
293: Thus there are usually minor security fixes in the current source code
294: beyond the previous major OpenBSD release. We make a limited
1.45 deraadt 295: guarantee that these problems are of minimal impact and unproven
1.44 ian 296: exploitability. If we discover that a problem definitely matters for
1.45 deraadt 297: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21 deraadt 298:
1.45 deraadt 299: People who are really concerned with security can do a number of
300: things:<p>
1.21 deraadt 301:
302: <ul>
303: <li>If you understand security issues, watch our
1.27 deraadt 304: <a href=mail.html>source-changes mailing list</a> and keep an
1.23 deraadt 305: eye out for things which appear security related. Since
1.21 deraadt 306: exploitability is not proven for many of the fixes we make,
307: do not expect the relevant commit message to say "SECURITY FIX!".
308: If a problem is proven and serious, a patch will be available
309: here very shortly after.
310: <li>Track our current source code tree, and teach yourself how to do a
1.29 deraadt 311: complete system build from time to time (read /usr/src/Makefile
312: carefully). Users can make the assumption that the current
313: source tree always has stronger security than the previous release.
1.45 deraadt 314: However, building your own system from source code is not trivial;
315: it is nearly 300MB of source code, and problems do occur as we
316: transition between major releases.
1.29 deraadt 317: <li>Install a binary <a href=snapshots.html>snapshot</a> for your
1.80 espie 318: architecture, which are made available fairly often. For
1.29 deraadt 319: instance, an i386 snapshot is typically made available weekly.
1.21 deraadt 320: </ul>
321:
1.9 deraadt 322: <p>
1.12 deraadt 323: <h3><font color=#e00000><strong>Other Resources</strong></font></h3>
1.3 deraadt 324:
1.5 deraadt 325: <p> If you find a new security problem, you can mail it to
1.6 deraadt 326: <a href=mailto:deraadt@openbsd.org>deraadt@openbsd.org</a>.
1.7 deraadt 327: <br>
1.5 deraadt 328: If you wish to PGP encode it (but please only do so if privacy is very
1.27 deraadt 329: urgent, since it is inconvenient) use this <a href=advisories/pgpkey>pgp key</a>.
1.5 deraadt 330:
1.2 deraadt 331: <hr>
1.68 pauls 332: <a href=index.html><img height=24 width=24 src=back.gif border=0 alt=OpenBSD></a>
1.24 deraadt 333: <a href=mailto:www@openbsd.org>www@openbsd.org</a>
334: <br>
1.102 ! deraadt 335: <small>$OpenBSD: security.html,v 1.101 1999/08/13 12:31:11 deraadt Exp $</small>
1.1 deraadt 336:
1.24 deraadt 337: </body>
338: </html>
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