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1.106 deraadt 17: <p>
1.294 david 18: <h2><font color="#e00000">Security</font></h2>
19: <hr>
1.1 deraadt 20:
1.406 deraadt 21: For security advisories for specific releases, click below:
1.294 david 22: <p>
1.406 deraadt 23:
1.418 tedu 24: <a href="errata20.html">2.0</a>,
25: <a href="errata21.html">2.1</a>,
26: <a href="errata22.html">2.2</a>,
27: <a href="errata23.html">2.3</a>,
28: <a href="errata24.html">2.4</a>,
29: <a href="errata25.html">2.5</a>,
30: <a href="errata26.html">2.6</a>,
31: <a href="errata27.html">2.7</a>,
32: <a href="errata28.html">2.8</a>,
33: <a href="errata29.html">2.9</a>,
34: <a href="errata30.html">3.0</a>,
35: <a href="errata31.html">3.1</a>,
36: <a href="errata32.html">3.2</a>,
37: <a href="errata33.html">3.3</a>,
38: <a href="errata34.html">3.4</a>,
39: <a href="errata35.html">3.5</a>,
40: <a href="errata36.html">3.6</a>,
1.365 deraadt 41: <br>
1.418 tedu 42: <a href="errata37.html">3.7</a>,
43: <a href="errata38.html">3.8</a>,
44: <a href="errata39.html">3.9</a>,
45: <a href="errata40.html">4.0</a>,
46: <a href="errata41.html">4.1</a>,
47: <a href="errata42.html">4.2</a>,
48: <a href="errata43.html">4.3</a>,
49: <a href="errata44.html">4.4</a>,
50: <a href="errata45.html">4.5</a>,
51: <a href="errata46.html">4.6</a>,
52: <a href="errata47.html">4.7</a>,
53: <a href="errata48.html">4.8</a>,
54: <a href="errata49.html">4.9</a>,
55: <a href="errata50.html">5.0</a>,
56: <a href="errata51.html">5.1</a>,
57: <a href="errata52.html">5.2</a>,
58: <a href="errata53.html">5.3</a>,
1.406 deraadt 59: <br>
1.418 tedu 60: <a href="errata54.html">5.4</a>,
1.419 ! jsg 61: <a href="errata55.html">5.5</a>,
! 62: <a href="errata56.html">5.6</a>.
1.406 deraadt 63: <br>
1.56 deraadt 64: <hr>
65:
1.294 david 66: <a name="goals"></a>
1.278 deraadt 67: <ul>
1.406 deraadt 68: <li><h3><font color="#e00000">Goals</font></h3><p>
1.22 deraadt 69:
1.14 deraadt 70: OpenBSD believes in strong security. Our aspiration is to be NUMBER
1.22 deraadt 71: ONE in the industry for security (if we are not already there). Our
72: open software development model permits us to take a more
73: uncompromising view towards increased security than Sun, SGI, IBM, HP,
74: or other vendors are able to. We can make changes the vendors would
1.27 deraadt 75: not make. Also, since OpenBSD is exported with <a href=crypto.html>
1.45 deraadt 76: cryptography</a>, we are able to take cryptographic approaches towards
77: fixing security problems.<p>
1.18 deraadt 78:
1.288 matthieu 79: <a name="disclosure"></a>
1.294 david 80: <li><h3><font color="#e00000">Full Disclosure</font></h3><p>
1.106 deraadt 81:
1.45 deraadt 82: Like many readers of the
1.196 jufi 83: <a href="http://online.securityfocus.com/archive/1">
1.18 deraadt 84: BUGTRAQ mailing list</a>,
1.106 deraadt 85: we believe in full disclosure of security problems. In the
86: operating system arena, we were probably the first to embrace
87: the concept. Many vendors, even of free software, still try
88: to hide issues from their users.<p>
89:
90: Security information moves very fast in cracker circles. On the other
91: hand, our experience is that coding and releasing of proper security
92: fixes typically requires about an hour of work -- very fast fix
93: turnaround is possible. Thus we think that full disclosure helps the
94: people who really care about security.<p>
95:
1.288 matthieu 96: <a name="process"></a>
1.294 david 97: <li><h3><font color="#e00000">Audit Process</font></h3><p>
1.15 deraadt 98:
1.12 deraadt 99: Our security auditing team typically has between six and twelve
1.45 deraadt 100: members who continue to search for and fix new security holes. We
101: have been auditing since the summer of 1996. The process we follow to
102: increase security is simply a comprehensive file-by-file analysis of
1.106 deraadt 103: every critical software component. We are not so much looking for
104: security holes, as we are looking for basic software bugs, and if
1.138 deraadt 105: years later someone discovers the problem used to be a security
1.106 deraadt 106: issue, and we fixed it because it was just a bug, well, all the
107: better. Flaws have been found in just about every area of the system.
108: Entire new classes of security problems have been found during our
109: audit, and often source code which had been audited earlier needs
110: re-auditing with these new flaws in mind. Code often gets audited
111: multiple times, and by multiple people with different auditing
112: skills.<p>
1.12 deraadt 113:
1.94 deraadt 114: Some members of our security auditing team worked for Secure Networks,
115: the company that made the industry's premier network security scanning
116: software package Ballista (Secure Networks got purchased by Network
117: Associates, Ballista got renamed to Cybercop Scanner, and well...)
118: That company did a lot of security research, and thus fit in well
1.106 deraadt 119: with the OpenBSD stance. OpenBSD passed Ballista's tests with flying
120: colours since day 1.<p>
1.31 deraadt 121:
1.34 deraadt 122: Another facet of our security auditing process is its proactiveness.
1.45 deraadt 123: In most cases we have found that the determination of exploitability
124: is not an issue. During our ongoing auditing process we find many
125: bugs, and endeavor to fix them even though exploitability is not
126: proven. We fix the bug, and we move on to find other bugs to fix. We
127: have fixed many simple and obvious careless programming errors in code
128: and only months later discovered that the problems were in fact
129: exploitable. (Or, more likely someone on
1.197 jufi 130: <a href="http://online.securityfocus.com/archive/1">BUGTRAQ</a>
1.45 deraadt 131: would report that other operating systems were vulnerable to a `newly
132: discovered problem', and then it would be discovered that OpenBSD had
133: been fixed in a previous release). In other cases we have been saved
134: from full exploitability of complex step-by-step attacks because we
135: had fixed one of the intermediate steps. An example of where we
1.94 deraadt 136: managed such a success is the lpd advisory that Secure Networks put out.
137: <p>
1.29 deraadt 138:
1.288 matthieu 139: <a name="newtech"></a>
1.294 david 140: <li><h3><font color="#e00000">New Technologies</font></h3><p>
1.278 deraadt 141:
142: As we audit source code, we often invent new ways of solving problems.
143: Sometimes these ideas have been used before in some random application
144: written somewhere, but perhaps not taken to the degree that we do.
145: <p>
146:
147: <ul>
148: <li>strlcpy() and strlcat()
149: <li>Memory protection purify
150: <ul>
151: <li>W^X
152: <li>.rodata segment
153: <li>Guard pages
154: <li>Randomized malloc()
155: <li>Randomized mmap()
156: <li>atexit() and stdio protection
157: </ul>
1.295 otto 158: <li>Privilege separation
1.278 deraadt 159: <li>Privilege revocation
160: <li>Chroot jailing
161: <li>New uids
162: <li>ProPolice
163: <li>... and others
164: </ul>
165: <p>
166:
1.294 david 167: <li><h3><font color="#e00000">The Reward</font></h3><p>
1.106 deraadt 168:
1.45 deraadt 169: Our proactive auditing process has really paid off. Statements like
1.35 deraadt 170: ``This problem was fixed in OpenBSD about 6 months ago'' have become
1.45 deraadt 171: commonplace in security forums like
1.197 jufi 172: <a href="http://online.securityfocus.com/archive/1">BUGTRAQ</a>.<p>
1.35 deraadt 173:
1.45 deraadt 174: The most intense part of our security auditing happened immediately
1.80 espie 175: before the OpenBSD 2.0 release and during the 2.0->2.1 transition,
1.45 deraadt 176: over the last third of 1996 and first half of 1997. Thousands (yes,
177: thousands) of security issues were fixed rapidly over this year-long
178: period; bugs like the standard buffer overflows, protocol
179: implementation weaknesses, information gathering, and filesystem
180: races. Hence most of the security problems that we encountered were
181: fixed before our 2.1 release, and then a far smaller number needed
182: fixing for our 2.2 release. We do not find as many problems anymore,
183: it is simply a case of diminishing returns. Recently the security
184: problems we find and fix tend to be significantly more obscure or
185: complicated. Still we will persist for a number of reasons:<p>
1.36 deraadt 186:
1.35 deraadt 187: <ul>
1.45 deraadt 188: <li>Occasionally we find a simple problem we missed earlier. Doh!
1.35 deraadt 189: <li>Security is like an arms race; the best attackers will continue
1.45 deraadt 190: to search for more complicated exploits, so we will too.
191: <li>Finding and fixing subtle flaws in complicated software is
192: a lot of fun.
1.35 deraadt 193: </ul>
1.106 deraadt 194: <p>
1.15 deraadt 195:
1.14 deraadt 196: The auditing process is not over yet, and as you can see we continue
1.28 deraadt 197: to find and fix new security flaws.<p>
1.12 deraadt 198:
1.288 matthieu 199: <a name="default"></a>
1.294 david 200: <li><h3><font color="#e00000">"Secure by Default"</font></h3><p>
1.106 deraadt 201:
202: To ensure that novice users of OpenBSD do not need to become security
203: experts overnight (a viewpoint which other vendors seem to have), we
204: ship the operating system in a Secure by Default mode. All non-essential
205: services are disabled. As the user/administrator becomes more familiar
206: with the system, he will discover that he has to enable daemons and other
207: parts of the system. During the process of learning how to enable a new
208: service, the novice is more likely to learn of security considerations.<p>
209:
210: This is in stark contrast to the increasing number of systems that
211: ship with NFS, mountd, web servers, and various other services enabled
212: by default, creating instantaneous security problems for their users
213: within minutes after their first install.<p>
214:
1.288 matthieu 215: <a name="crypto"></a>
1.294 david 216: <li><h3><font color="#e00000">Cryptography</font></h3><p>
1.106 deraadt 217:
218: And of course, since the OpenBSD project is based in Canada, it is possible
219: for us to integrate cryptography. For more information, read the page
1.116 deraadt 220: outlining <a href=crypto.html>what we have done with cryptography</a>.</p>
1.106 deraadt 221:
1.294 david 222: <li><h3><font color="#e00000">Advisories</font></h3><p>
1.106 deraadt 223:
1.418 tedu 224: Please refer to the links at the top of this page.
1.106 deraadt 225:
1.288 matthieu 226: <a name="watching"></a>
1.294 david 227: <li><h3><font color="#e00000">Watching our Changes</font></h3><p>
1.106 deraadt 228:
1.21 deraadt 229: Since we take a proactive stance with security, we are continually
230: finding and fixing new security problems. Not all of these problems
1.80 espie 231: get widely reported because (as stated earlier) many of them are not
1.45 deraadt 232: confirmed to be exploitable; many simple bugs we fix do turn out to
233: have security consequences we could not predict. We do not have the
234: time resources to make these changes available in the above format.<p>
1.21 deraadt 235:
236: Thus there are usually minor security fixes in the current source code
237: beyond the previous major OpenBSD release. We make a limited
1.45 deraadt 238: guarantee that these problems are of minimal impact and unproven
1.44 ian 239: exploitability. If we discover that a problem definitely matters for
1.45 deraadt 240: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21 deraadt 241:
1.45 deraadt 242: People who are really concerned with security can do a number of
243: things:<p>
1.21 deraadt 244:
245: <ul>
246: <li>If you understand security issues, watch our
1.294 david 247: <a href="mail.html">source-changes mailing list</a> and keep an
1.23 deraadt 248: eye out for things which appear security related. Since
1.21 deraadt 249: exploitability is not proven for many of the fixes we make,
250: do not expect the relevant commit message to say "SECURITY FIX!".
251: If a problem is proven and serious, a patch will be available
252: here very shortly after.
1.161 horacio 253: <li>In addition to source changes, you can watch our <a href="mail.html">
1.160 ericj 254: security-announce mailing list</a> which will notify you for every
1.186 ian 255: security related item that the OpenBSD team deems as a possible threat,
1.160 ericj 256: and instruct you on how to patch the problem.
1.21 deraadt 257: <li>Track our current source code tree, and teach yourself how to do a
1.29 deraadt 258: complete system build from time to time (read /usr/src/Makefile
259: carefully). Users can make the assumption that the current
260: source tree always has stronger security than the previous release.
1.45 deraadt 261: However, building your own system from source code is not trivial;
1.397 deraadt 262: it is nearly 850MB of source code, and problems do occur as we
1.45 deraadt 263: transition between major releases.
1.115 ericj 264: <li>Install a binary snapshot for your
1.80 espie 265: architecture, which are made available fairly often. For
1.413 matthieu 266: instance, an i386 snapshot is typically made available weekly.
1.21 deraadt 267: </ul>
268:
1.9 deraadt 269: <p>
1.288 matthieu 270: <a name="reporting"></a>
1.294 david 271: <li><h3><font color="#e00000">Reporting problems</font></h3><p>
1.3 deraadt 272:
1.5 deraadt 273: <p> If you find a new security problem, you can mail it to
1.294 david 274: <a href="mailto:deraadt@openbsd.org">deraadt@openbsd.org</a>.
1.7 deraadt 275: <br>
1.5 deraadt 276: If you wish to PGP encode it (but please only do so if privacy is very
1.112 philen 277: urgent, since it is inconvenient) use this <a href="advisories/pgpkey.txt">pgp key</a>.
1.5 deraadt 278:
1.107 deraadt 279: <p>
1.288 matthieu 280: <a name="papers"></a>
1.294 david 281: <li><h3><font color="#e00000">Further Reading</font></h3><p>
1.107 deraadt 282:
1.389 lum 283: Numerous
1.404 deraadt 284: <a href="papers/index.html">papers</a> have been written by OpenBSD team members,
1.389 lum 285: many dedicated to security.
1.294 david 286: </ul>
1.1 deraadt 287:
1.24 deraadt 288: </body>
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