Annotation of www/security.html, Revision 1.437
1.294 david 1: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2: "http://www.w3.org/TR/html4/loose.dtd">
1.1 deraadt 3: <html>
4: <head>
1.430 tj 5: <title>OpenBSD: Security</title>
1.294 david 6: <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
1.430 tj 7: <meta name="copyright" content="This document copyright 1997-2016 by OpenBSD.">
1.425 deraadt 8: <meta name="viewport" content="width=device-width, initial-scale=1">
9: <link rel="stylesheet" type="text/css" href="openbsd.css">
1.432 tb 10: <link rel="canonical" href="https://www.openbsd.org/security.html">
1.1 deraadt 11: </head>
12:
1.428 tb 13: <body bgcolor="#ffffff" text="#000000" link="#23238e">
14:
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>,
1.435 deraadt 68: <a href="errata61.html">6.1</a>,
1.436 deraadt 69: <a href="errata62.html">6.2</a>,
1.437 ! deraadt 70: <a href="errata63.html">6.3</a>,
! 71: <a href="errata64.html">6.4</a>.
1.406 deraadt 72: <br>
1.56 deraadt 73: <hr>
74:
1.294 david 75: <a name="goals"></a>
1.278 deraadt 76: <ul>
1.406 deraadt 77: <li><h3><font color="#e00000">Goals</font></h3><p>
1.22 deraadt 78:
1.14 deraadt 79: OpenBSD believes in strong security. Our aspiration is to be NUMBER
1.22 deraadt 80: ONE in the industry for security (if we are not already there). Our
81: open software development model permits us to take a more
1.424 tb 82: uncompromising view towards increased security than most vendors are
83: able to. We can make changes the vendors would
1.27 deraadt 84: not make. Also, since OpenBSD is exported with <a href=crypto.html>
1.45 deraadt 85: cryptography</a>, we are able to take cryptographic approaches towards
86: fixing security problems.<p>
1.18 deraadt 87:
1.288 matthieu 88: <a name="disclosure"></a>
1.294 david 89: <li><h3><font color="#e00000">Full Disclosure</font></h3><p>
1.106 deraadt 90:
1.45 deraadt 91: Like many readers of the
1.196 jufi 92: <a href="http://online.securityfocus.com/archive/1">
1.18 deraadt 93: BUGTRAQ mailing list</a>,
1.106 deraadt 94: we believe in full disclosure of security problems. In the
95: operating system arena, we were probably the first to embrace
96: the concept. Many vendors, even of free software, still try
97: to hide issues from their users.<p>
98:
99: Security information moves very fast in cracker circles. On the other
100: hand, our experience is that coding and releasing of proper security
101: fixes typically requires about an hour of work -- very fast fix
102: turnaround is possible. Thus we think that full disclosure helps the
103: people who really care about security.<p>
104:
1.288 matthieu 105: <a name="process"></a>
1.294 david 106: <li><h3><font color="#e00000">Audit Process</font></h3><p>
1.15 deraadt 107:
1.12 deraadt 108: Our security auditing team typically has between six and twelve
1.45 deraadt 109: members who continue to search for and fix new security holes. We
110: have been auditing since the summer of 1996. The process we follow to
111: increase security is simply a comprehensive file-by-file analysis of
1.106 deraadt 112: every critical software component. We are not so much looking for
113: security holes, as we are looking for basic software bugs, and if
1.138 deraadt 114: years later someone discovers the problem used to be a security
1.106 deraadt 115: issue, and we fixed it because it was just a bug, well, all the
116: better. Flaws have been found in just about every area of the system.
117: Entire new classes of security problems have been found during our
118: audit, and often source code which had been audited earlier needs
119: re-auditing with these new flaws in mind. Code often gets audited
120: multiple times, and by multiple people with different auditing
121: skills.<p>
1.12 deraadt 122:
1.94 deraadt 123: Some members of our security auditing team worked for Secure Networks,
124: the company that made the industry's premier network security scanning
125: software package Ballista (Secure Networks got purchased by Network
126: Associates, Ballista got renamed to Cybercop Scanner, and well...)
127: That company did a lot of security research, and thus fit in well
1.106 deraadt 128: with the OpenBSD stance. OpenBSD passed Ballista's tests with flying
129: colours since day 1.<p>
1.31 deraadt 130:
1.34 deraadt 131: Another facet of our security auditing process is its proactiveness.
1.45 deraadt 132: In most cases we have found that the determination of exploitability
133: is not an issue. During our ongoing auditing process we find many
134: bugs, and endeavor to fix them even though exploitability is not
135: proven. We fix the bug, and we move on to find other bugs to fix. We
136: have fixed many simple and obvious careless programming errors in code
137: and only months later discovered that the problems were in fact
138: exploitable. (Or, more likely someone on
1.197 jufi 139: <a href="http://online.securityfocus.com/archive/1">BUGTRAQ</a>
1.45 deraadt 140: would report that other operating systems were vulnerable to a `newly
141: discovered problem', and then it would be discovered that OpenBSD had
142: been fixed in a previous release). In other cases we have been saved
143: from full exploitability of complex step-by-step attacks because we
144: had fixed one of the intermediate steps. An example of where we
1.94 deraadt 145: managed such a success is the lpd advisory that Secure Networks put out.
146: <p>
1.29 deraadt 147:
1.288 matthieu 148: <a name="newtech"></a>
1.294 david 149: <li><h3><font color="#e00000">New Technologies</font></h3><p>
1.278 deraadt 150:
151: As we audit source code, we often invent new ways of solving problems.
152: Sometimes these ideas have been used before in some random application
153: written somewhere, but perhaps not taken to the degree that we do.
154: <p>
155:
156: <ul>
157: <li>strlcpy() and strlcat()
158: <li>Memory protection purify
159: <ul>
160: <li>W^X
161: <li>.rodata segment
162: <li>Guard pages
163: <li>Randomized malloc()
164: <li>Randomized mmap()
165: <li>atexit() and stdio protection
166: </ul>
1.295 otto 167: <li>Privilege separation
1.278 deraadt 168: <li>Privilege revocation
169: <li>Chroot jailing
170: <li>New uids
171: <li>ProPolice
1.424 tb 172: <li>... <a href="/innovations.html">and others</a>
1.278 deraadt 173: </ul>
174: <p>
175:
1.294 david 176: <li><h3><font color="#e00000">The Reward</font></h3><p>
1.106 deraadt 177:
1.45 deraadt 178: Our proactive auditing process has really paid off. Statements like
1.35 deraadt 179: ``This problem was fixed in OpenBSD about 6 months ago'' have become
1.45 deraadt 180: commonplace in security forums like
1.197 jufi 181: <a href="http://online.securityfocus.com/archive/1">BUGTRAQ</a>.<p>
1.35 deraadt 182:
1.45 deraadt 183: The most intense part of our security auditing happened immediately
1.80 espie 184: before the OpenBSD 2.0 release and during the 2.0->2.1 transition,
1.45 deraadt 185: over the last third of 1996 and first half of 1997. Thousands (yes,
186: thousands) of security issues were fixed rapidly over this year-long
187: period; bugs like the standard buffer overflows, protocol
188: implementation weaknesses, information gathering, and filesystem
189: races. Hence most of the security problems that we encountered were
190: fixed before our 2.1 release, and then a far smaller number needed
191: fixing for our 2.2 release. We do not find as many problems anymore,
192: it is simply a case of diminishing returns. Recently the security
193: problems we find and fix tend to be significantly more obscure or
194: complicated. Still we will persist for a number of reasons:<p>
1.36 deraadt 195:
1.35 deraadt 196: <ul>
1.45 deraadt 197: <li>Occasionally we find a simple problem we missed earlier. Doh!
1.35 deraadt 198: <li>Security is like an arms race; the best attackers will continue
1.45 deraadt 199: to search for more complicated exploits, so we will too.
200: <li>Finding and fixing subtle flaws in complicated software is
201: a lot of fun.
1.35 deraadt 202: </ul>
1.106 deraadt 203: <p>
1.15 deraadt 204:
1.14 deraadt 205: The auditing process is not over yet, and as you can see we continue
1.28 deraadt 206: to find and fix new security flaws.<p>
1.12 deraadt 207:
1.288 matthieu 208: <a name="default"></a>
1.294 david 209: <li><h3><font color="#e00000">"Secure by Default"</font></h3><p>
1.106 deraadt 210:
211: To ensure that novice users of OpenBSD do not need to become security
212: experts overnight (a viewpoint which other vendors seem to have), we
213: ship the operating system in a Secure by Default mode. All non-essential
214: services are disabled. As the user/administrator becomes more familiar
215: with the system, he will discover that he has to enable daemons and other
216: parts of the system. During the process of learning how to enable a new
217: service, the novice is more likely to learn of security considerations.<p>
218:
219: This is in stark contrast to the increasing number of systems that
220: ship with NFS, mountd, web servers, and various other services enabled
221: by default, creating instantaneous security problems for their users
222: within minutes after their first install.<p>
223:
1.288 matthieu 224: <a name="crypto"></a>
1.294 david 225: <li><h3><font color="#e00000">Cryptography</font></h3><p>
1.106 deraadt 226:
227: And of course, since the OpenBSD project is based in Canada, it is possible
228: for us to integrate cryptography. For more information, read the page
1.116 deraadt 229: outlining <a href=crypto.html>what we have done with cryptography</a>.</p>
1.106 deraadt 230:
1.294 david 231: <li><h3><font color="#e00000">Advisories</font></h3><p>
1.106 deraadt 232:
1.418 tedu 233: Please refer to the links at the top of this page.
1.106 deraadt 234:
1.288 matthieu 235: <a name="watching"></a>
1.294 david 236: <li><h3><font color="#e00000">Watching our Changes</font></h3><p>
1.106 deraadt 237:
1.21 deraadt 238: Since we take a proactive stance with security, we are continually
239: finding and fixing new security problems. Not all of these problems
1.80 espie 240: get widely reported because (as stated earlier) many of them are not
1.45 deraadt 241: confirmed to be exploitable; many simple bugs we fix do turn out to
242: have security consequences we could not predict. We do not have the
243: time resources to make these changes available in the above format.<p>
1.21 deraadt 244:
245: Thus there are usually minor security fixes in the current source code
246: beyond the previous major OpenBSD release. We make a limited
1.45 deraadt 247: guarantee that these problems are of minimal impact and unproven
1.44 ian 248: exploitability. If we discover that a problem definitely matters for
1.45 deraadt 249: security, patches will show up here <strong>VERY</strong> quickly.<p>
1.21 deraadt 250:
1.45 deraadt 251: People who are really concerned with security can do a number of
252: things:<p>
1.21 deraadt 253:
254: <ul>
255: <li>If you understand security issues, watch our
1.294 david 256: <a href="mail.html">source-changes mailing list</a> and keep an
1.23 deraadt 257: eye out for things which appear security related. Since
1.21 deraadt 258: exploitability is not proven for many of the fixes we make,
259: do not expect the relevant commit message to say "SECURITY FIX!".
260: If a problem is proven and serious, a patch will be available
261: here very shortly after.
262: <li>Track our current source code tree, and teach yourself how to do a
1.29 deraadt 263: complete system build from time to time (read /usr/src/Makefile
264: carefully). Users can make the assumption that the current
265: source tree always has stronger security than the previous release.
1.45 deraadt 266: However, building your own system from source code is not trivial;
1.424 tb 267: it is over 850MB of source code, and problems do occur as we
1.45 deraadt 268: transition between major releases.
1.115 ericj 269: <li>Install a binary snapshot for your
1.80 espie 270: architecture, which are made available fairly often. For
1.424 tb 271: instance, an amd64 snapshot is typically made available daily.
1.21 deraadt 272: </ul>
273:
1.9 deraadt 274: <p>
1.288 matthieu 275: <a name="reporting"></a>
1.294 david 276: <li><h3><font color="#e00000">Reporting problems</font></h3><p>
1.3 deraadt 277:
1.5 deraadt 278: <p> If you find a new security problem, you can mail it to
1.294 david 279: <a href="mailto:deraadt@openbsd.org">deraadt@openbsd.org</a>.
1.7 deraadt 280: <br>
1.5 deraadt 281: If you wish to PGP encode it (but please only do so if privacy is very
1.112 philen 282: urgent, since it is inconvenient) use this <a href="advisories/pgpkey.txt">pgp key</a>.
1.5 deraadt 283:
1.107 deraadt 284: <p>
1.288 matthieu 285: <a name="papers"></a>
1.294 david 286: <li><h3><font color="#e00000">Further Reading</font></h3><p>
1.107 deraadt 287:
1.389 lum 288: Numerous
1.404 deraadt 289: <a href="papers/index.html">papers</a> have been written by OpenBSD team members,
1.389 lum 290: many dedicated to security.
1.294 david 291: </ul>
1.1 deraadt 292:
1.24 deraadt 293: </body>
294: </html>
![[BACK]](/icons/back.gif){kind=icon}
Return to security.html CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / www