-----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-00:08 Security Advisory FreeBSD, Inc. Topic: Lynx ports contain numerous buffer overflows Category: ports Module: lynx/lynx-current/lynx-ssl/ja-lynx/ja-lynx-current Announced: 2000-03-15 Revised: 2000-05-17 Affects: Ports collection before the correction date. Corrected: 2000-04-16 [lynx-current] 2000-04-21 [lynx] FreeBSD only: NO I. Background Lynx is a popular text-mode WWW browser, available in several versions including SSL support and Japanese language localization. II. Problem Description Versions of the lynx software prior to version 2.8.3pre.5 were written in a very insecure style and contain numerous potential and several proven security vulnerabilities (publicized on the BugTraq mailing list) exploitable by a malicious server. The lynx ports are not installed by default, nor are they "part of FreeBSD" as such: they are part of the FreeBSD ports collection, which contains over 3200 third-party applications in a ready-to-install format. FreeBSD makes no claim about the security of these third-party applications, although an effort is underway to provide a security audit of the most security-critical ports. III. Impact A malicious server which is visited by a user with the lynx browser can exploit the browser security holes in order to execute arbitrary code as the local user. If you have not chosen to install any of the lynx/lynx-current/lynx-ssl/ja-lynx/ja-lynx-current ports/packages, then your system is not vulnerable. IV. Workaround Remove the lynx/lynx-current/lynx-ssl/ja-lynx/ja-lynx-current ports, if you you have installed them. V. Solution Upgrade to lynx or lynx-current after the correction date. After the initial release of this advisory, the Lynx development team conducted an audit of the source code, and have corrected the known vulnerabilities in lynx as well as increasing the robustness of the string-handling code. As of lynx-2.8.3pre.5, we consider it safe enough to use again. Note that there may be undiscovered vulnerabilities remaining in the code, as with all software - but should any further vulnerabilities be discovered a new advisory will be issued. At this time the lynx-ssl/ja-lynx/ja-lynx-current ports are not yet updated to a safe version of lynx: this advisory will be reissued again once they are. 1) Upgrade your entire ports collection and rebuild the lynx or lynx-current port. 2) Reinstall a lynx new package dated after the correction date, obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/www/lynx-2.8.3.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/www/lynx-2.8.3.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/www/lynx-2.8.3.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/www/lynx-2.8.3.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/www/lynx-2.8.3.1.tgz Note that the lynx-current port is not automatically built as a package. 3) download a new port skeleton for the lynx/lynx-current port from: http://www.freebsd.org/ports/ and use it to rebuild the port. 4) Use the portcheckout utility to automate option (3) above. The portcheckout port is available in /usr/ports/devel/portcheckout or the package can be obtained from: ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/devel/portcheckout-1.0.tgz VI. Revision History v1.0 2000-03-15 Initial release v1.1 2000-05-17 Update to note fix of lynx and lynx-current ports. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBOSMQT1UuHi5z0oilAQHlgwP9EiLqvf8MM55fvftEXPMfL6PJ6HFQPYMH +TqX5Q/P9s0mgBFiGfN8wblmtEUyZ1GwF8goPa9fqqJIfNg8Qu2zWqJOYPjc20hW yo3Rxbi+lEWOYxLpxBKDhvBH7yWxiV8Nm1+w73a76BjaZ20E0b91hgw2lebFiZPi uzK38WjnFNQ= =qWEC -----END PGP SIGNATURE-----