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1.425 deraadt 15: <h2>
16: <a href="index.html">
17: <i><font color="#0000ff">Open</font></i><font color="#000084">BSD</font></a>
18: <font color="#e00000">Security</font>
1.427 tb 19: </h2>
1.294 david 20: <hr>
1.429 tj 21: <p>
1.1 deraadt 22:
1.406 deraadt 23: For security advisories for specific releases, click below:
1.294 david 24: <p>
1.406 deraadt 25:
1.418 tedu 26: <a href="errata21.html">2.1</a>,
27: <a href="errata22.html">2.2</a>,
28: <a href="errata23.html">2.3</a>,
29: <a href="errata24.html">2.4</a>,
30: <a href="errata25.html">2.5</a>,
31: <a href="errata26.html">2.6</a>,
32: <a href="errata27.html">2.7</a>,
33: <a href="errata28.html">2.8</a>,
34: <a href="errata29.html">2.9</a>,
35: <a href="errata30.html">3.0</a>,
36: <a href="errata31.html">3.1</a>,
37: <a href="errata32.html">3.2</a>,
38: <a href="errata33.html">3.3</a>,
39: <a href="errata34.html">3.4</a>,
40: <a href="errata35.html">3.5</a>,
41: <a href="errata36.html">3.6</a>,
1.420 schwarze 42: <a href="errata37.html">3.7</a>,
1.365 deraadt 43: <br>
1.418 tedu 44: <a href="errata38.html">3.8</a>,
45: <a href="errata39.html">3.9</a>,
46: <a href="errata40.html">4.0</a>,
47: <a href="errata41.html">4.1</a>,
48: <a href="errata42.html">4.2</a>,
49: <a href="errata43.html">4.3</a>,
50: <a href="errata44.html">4.4</a>,
51: <a href="errata45.html">4.5</a>,
52: <a href="errata46.html">4.6</a>,
53: <a href="errata47.html">4.7</a>,
54: <a href="errata48.html">4.8</a>,
55: <a href="errata49.html">4.9</a>,
56: <a href="errata50.html">5.0</a>,
57: <a href="errata51.html">5.1</a>,
58: <a href="errata52.html">5.2</a>,
59: <a href="errata53.html">5.3</a>,
1.420 schwarze 60: <a href="errata54.html">5.4</a>,
1.406 deraadt 61: <br>
1.419 jsg 62: <a href="errata55.html">5.5</a>,
1.420 schwarze 63: <a href="errata56.html">5.6</a>,
1.423 benno 64: <a href="errata57.html">5.7</a>,
1.431 deraadt 65: <a href="errata58.html">5.8</a>,
66: <a href="errata59.html">5.9</a>,
1.434 ! tj 67: <a href="errata60.html">6.0</a>,
! 68: <a href="errata61.html">6.1</a>.
1.406 deraadt 69: <br>
1.56 deraadt 70: <hr>
71:
1.294 david 72: <a name="goals"></a>
1.278 deraadt 73: <ul>
1.406 deraadt 74: <li><h3><font color="#e00000">Goals</font></h3><p>
1.22 deraadt 75:
1.14 deraadt 76: OpenBSD believes in strong security. Our aspiration is to be NUMBER
1.22 deraadt 77: ONE in the industry for security (if we are not already there). Our
78: open software development model permits us to take a more
1.424 tb 79: uncompromising view towards increased security than most vendors are
80: able to. We can make changes the vendors would
1.27 deraadt 81: not make. Also, since OpenBSD is exported with <a href=crypto.html>
1.45 deraadt 82: cryptography</a>, we are able to take cryptographic approaches towards
83: fixing security problems.<p>
1.18 deraadt 84:
1.288 matthieu 85: <a name="disclosure"></a>
1.294 david 86: <li><h3><font color="#e00000">Full Disclosure</font></h3><p>
1.106 deraadt 87:
1.45 deraadt 88: Like many readers of the
1.196 jufi 89: <a href="http://online.securityfocus.com/archive/1">
1.18 deraadt 90: BUGTRAQ mailing list</a>,
1.106 deraadt 91: we believe in full disclosure of security problems. In the
92: operating system arena, we were probably the first to embrace
93: the concept. Many vendors, even of free software, still try
94: to hide issues from their users.<p>
95:
96: Security information moves very fast in cracker circles. On the other
97: hand, our experience is that coding and releasing of proper security
98: fixes typically requires about an hour of work -- very fast fix
99: turnaround is possible. Thus we think that full disclosure helps the
100: people who really care about security.<p>
101:
1.288 matthieu 102: <a name="process"></a>
1.294 david 103: <li><h3><font color="#e00000">Audit Process</font></h3><p>
1.15 deraadt 104:
1.12 deraadt 105: Our security auditing team typically has between six and twelve
1.45 deraadt 106: members who continue to search for and fix new security holes. We
107: have been auditing since the summer of 1996. The process we follow to
108: increase security is simply a comprehensive file-by-file analysis of
1.106 deraadt 109: every critical software component. We are not so much looking for
110: security holes, as we are looking for basic software bugs, and if
1.138 deraadt 111: years later someone discovers the problem used to be a security
1.106 deraadt 112: issue, and we fixed it because it was just a bug, well, all the
113: better. Flaws have been found in just about every area of the system.
114: Entire new classes of security problems have been found during our
115: audit, and often source code which had been audited earlier needs
116: re-auditing with these new flaws in mind. Code often gets audited
117: multiple times, and by multiple people with different auditing
118: skills.<p>
1.12 deraadt 119:
1.94 deraadt 120: Some members of our security auditing team worked for Secure Networks,
121: the company that made the industry's premier network security scanning
122: software package Ballista (Secure Networks got purchased by Network
123: Associates, Ballista got renamed to Cybercop Scanner, and well...)
124: That company did a lot of security research, and thus fit in well
1.106 deraadt 125: with the OpenBSD stance. OpenBSD passed Ballista's tests with flying
126: colours since day 1.<p>
1.31 deraadt 127:
1.34 deraadt 128: Another facet of our security auditing process is its proactiveness.
1.45 deraadt 129: In most cases we have found that the determination of exploitability
130: is not an issue. During our ongoing auditing process we find many
131: bugs, and endeavor to fix them even though exploitability is not
132: proven. We fix the bug, and we move on to find other bugs to fix. We
133: have fixed many simple and obvious careless programming errors in code
134: and only months later discovered that the problems were in fact
135: exploitable. (Or, more likely someone on
1.197 jufi 136: <a href="http://online.securityfocus.com/archive/1">BUGTRAQ</a>
1.45 deraadt 137: would report that other operating systems were vulnerable to a `newly
138: discovered problem', and then it would be discovered that OpenBSD had
139: been fixed in a previous release). In other cases we have been saved
140: from full exploitability of complex step-by-step attacks because we
141: had fixed one of the intermediate steps. An example of where we
1.94 deraadt 142: managed such a success is the lpd advisory that Secure Networks put out.
143: <p>
1.29 deraadt 144:
1.288 matthieu 145: <a name="newtech"></a>
1.294 david 146: <li><h3><font color="#e00000">New Technologies</font></h3><p>
1.278 deraadt 147:
148: As we audit source code, we often invent new ways of solving problems.
149: Sometimes these ideas have been used before in some random application
150: written somewhere, but perhaps not taken to the degree that we do.
151: <p>
152:
153: <ul>
154: <li>strlcpy() and strlcat()
155: <li>Memory protection purify
156: <ul>
157: <li>W^X
158: <li>.rodata segment
159: <li>Guard pages
160: <li>Randomized malloc()
161: <li>Randomized mmap()
162: <li>atexit() and stdio protection
163: </ul>
1.295 otto 164: <li>Privilege separation
1.278 deraadt 165: <li>Privilege revocation
166: <li>Chroot jailing
167: <li>New uids
168: <li>ProPolice
1.424 tb 169: <li>... <a href="/innovations.html">and others</a>
1.278 deraadt 170: </ul>
171: <p>
172:
1.294 david 173: <li><h3><font color="#e00000">The Reward</font></h3><p>
1.106 deraadt 174:
1.45 deraadt 175: Our proactive auditing process has really paid off. Statements like
1.35 deraadt 176: ``This problem was fixed in OpenBSD about 6 months ago'' have become
1.45 deraadt 177: commonplace in security forums like
1.197 jufi 178: <a href="http://online.securityfocus.com/archive/1">BUGTRAQ</a>.<p>
1.35 deraadt 179:
1.45 deraadt 180: The most intense part of our security auditing happened immediately
1.80 espie 181: before the OpenBSD 2.0 release and during the 2.0->2.1 transition,
1.45 deraadt 182: over the last third of 1996 and first half of 1997. Thousands (yes,
183: thousands) of security issues were fixed rapidly over this year-long
184: period; bugs like the standard buffer overflows, protocol
185: implementation weaknesses, information gathering, and filesystem
186: races. Hence most of the security problems that we encountered were
187: fixed before our 2.1 release, and then a far smaller number needed
188: fixing for our 2.2 release. We do not find as many problems anymore,
189: it is simply a case of diminishing returns. Recently the security
190: problems we find and fix tend to be significantly more obscure or
191: complicated. Still we will persist for a number of reasons:<p>
1.36 deraadt 192:
1.35 deraadt 193: <ul>
1.45 deraadt 194: <li>Occasionally we find a simple problem we missed earlier. Doh!
1.35 deraadt 195: <li>Security is like an arms race; the best attackers will continue
1.45 deraadt 196: to search for more complicated exploits, so we will too.
197: <li>Finding and fixing subtle flaws in complicated software is
198: a lot of fun.
1.35 deraadt 199: </ul>
1.106 deraadt 200: <p>
1.15 deraadt 201:
1.14 deraadt 202: The auditing process is not over yet, and as you can see we continue
1.28 deraadt 203: to find and fix new security flaws.<p>
1.12 deraadt 204:
1.288 matthieu 205: <a name="default"></a>
1.294 david 206: <li><h3><font color="#e00000">"Secure by Default"</font></h3><p>
1.106 deraadt 207:
208: To ensure that novice users of OpenBSD do not need to become security
209: experts overnight (a viewpoint which other vendors seem to have), we
210: ship the operating system in a Secure by Default mode. All non-essential
211: services are disabled. As the user/administrator becomes more familiar
212: with the system, he will discover that he has to enable daemons and other
213: parts of the system. During the process of learning how to enable a new
214: service, the novice is more likely to learn of security considerations.<p>
215:
216: This is in stark contrast to the increasing number of systems that
217: ship with NFS, mountd, web servers, and various other services enabled
218: by default, creating instantaneous security problems for their users
219: within minutes after their first install.<p>
220:
1.288 matthieu 221: <a name="crypto"></a>
1.294 david 222: <li><h3><font color="#e00000">Cryptography</font></h3><p>
1.106 deraadt 223:
224: And of course, since the OpenBSD project is based in Canada, it is possible
225: for us to integrate cryptography. For more information, read the page
1.116 deraadt 226: outlining <a href=crypto.html>what we have done with cryptography</a>.</p>
1.106 deraadt 227:
1.294 david 228: <li><h3><font color="#e00000">Advisories</font></h3><p>
1.106 deraadt 229:
1.418 tedu 230: Please refer to the links at the top of this page.
1.106 deraadt 231:
1.288 matthieu 232: <a name="watching"></a>
1.294 david 233: <li><h3><font color="#e00000">Watching our Changes</font></h3><p>
1.106 deraadt 234:
1.21 deraadt 235: Since we take a proactive stance with security, we are continually
236: finding and fixing new security problems. Not all of these problems
1.80 espie 237: get widely reported because (as stated earlier) many of them are not
1.45 deraadt 238: confirmed to be exploitable; many simple bugs we fix do turn out to
239: have security consequences we could not predict. We do not have the
240: time resources to make these changes available in the above format.<p>
1.21 deraadt 241:
242: Thus there are usually minor security fixes in the current source code
243: beyond the previous major OpenBSD release. We make a limited
1.45 deraadt 244: guarantee that these problems are of minimal impact and unproven
1.44 ian 245: exploitability. If we discover that a problem definitely matters for
1.45 deraadt 246: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21 deraadt 247:
1.45 deraadt 248: People who are really concerned with security can do a number of
249: things:<p>
1.21 deraadt 250:
251: <ul>
252: <li>If you understand security issues, watch our
1.294 david 253: <a href="mail.html">source-changes mailing list</a> and keep an
1.23 deraadt 254: eye out for things which appear security related. Since
1.21 deraadt 255: exploitability is not proven for many of the fixes we make,
256: do not expect the relevant commit message to say "SECURITY FIX!".
257: If a problem is proven and serious, a patch will be available
258: here very shortly after.
259: <li>Track our current source code tree, and teach yourself how to do a
1.29 deraadt 260: complete system build from time to time (read /usr/src/Makefile
261: carefully). Users can make the assumption that the current
262: source tree always has stronger security than the previous release.
1.45 deraadt 263: However, building your own system from source code is not trivial;
1.424 tb 264: it is over 850MB of source code, and problems do occur as we
1.45 deraadt 265: transition between major releases.
1.115 ericj 266: <li>Install a binary snapshot for your
1.80 espie 267: architecture, which are made available fairly often. For
1.424 tb 268: instance, an amd64 snapshot is typically made available daily.
1.21 deraadt 269: </ul>
270:
1.9 deraadt 271: <p>
1.288 matthieu 272: <a name="reporting"></a>
1.294 david 273: <li><h3><font color="#e00000">Reporting problems</font></h3><p>
1.3 deraadt 274:
1.5 deraadt 275: <p> If you find a new security problem, you can mail it to
1.294 david 276: <a href="mailto:deraadt@openbsd.org">deraadt@openbsd.org</a>.
1.7 deraadt 277: <br>
1.5 deraadt 278: If you wish to PGP encode it (but please only do so if privacy is very
1.112 philen 279: urgent, since it is inconvenient) use this <a href="advisories/pgpkey.txt">pgp key</a>.
1.5 deraadt 280:
1.107 deraadt 281: <p>
1.288 matthieu 282: <a name="papers"></a>
1.294 david 283: <li><h3><font color="#e00000">Further Reading</font></h3><p>
1.107 deraadt 284:
1.389 lum 285: Numerous
1.404 deraadt 286: <a href="papers/index.html">papers</a> have been written by OpenBSD team members,
1.389 lum 287: many dedicated to security.
1.294 david 288: </ul>
1.1 deraadt 289:
1.24 deraadt 290: </body>
291: </html>
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