[ SOURCE: http://www.secureroot.com/security/advisories/9749180504.html ] -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-00:73 Security Advisory FreeBSD, Inc. Topic: thttpd allows remote reading of local files Category: ports Module: thttpd Announced: 2000-11-20 Credits: ghandi@MINDLESS.COM Affects: Ports collection prior to the correction date. Corrected: 2000-10-30 Vendor status: Updated version released FreeBSD only: NO I. Background thttpd is a simple, small, fast HTTP server. II. Problem Description The thttpd port, versions prior to 2.20, allows remote viewing of arbitrary files on the local server. The 'ssi' cgi script does not correctly restrict URL-encoded requests containing ".." in the path. In addition, the cgi script does not have the same restrictions as the web server for preventing requests outside of the web root. These two flaws allow remote users to access any file on the system accessible to the web server user (user 'nobody' in the default configuration). The thttpd port is not installed by default, nor is it "part of FreeBSD" as such: it is part of the FreeBSD ports collection, which contains over 4100 third-party applications in a ready-to-install format. The ports collections shipped with FreeBSD 3.5.1 and 4.1.1 contain this problem since it was discovered after the releases, but it was corrected prior to the release of FreeBSD 4.2. 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 Remote users may access any file on the system accessible to the web server user (user 'nobody' in the default installation). If you have not chosen to install the thttpd port/package, then your system is not vulnerable to this problem. IV. Workaround Deinstall the thttpd port/package, if you you have installed it. V. Solution One of the following: 1) Upgrade your entire ports collection and rebuild the thttpd port. 2) Deinstall the old package and install a new package dated after the correction date, obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/www/thttpd-2.20b.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/www/thttpd-2.20b.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/www/thttpd-2.20b.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/www/thttpd-2.20b.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/www/thttpd-2.20b.tgz 3) download a new port skeleton for the thttpd 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/i386/packages-3-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/devel/portcheckout-2.0.tgz -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBOhmWNFUuHi5z0oilAQF1sQP9Fc/jBFjSNhzGIGc+bglEOiepdajSk3Ep wtoLUQJug56qcbUtxgg6FxbDv7xW/uYZ1YKWYQsjAr0tyYv+zTSVgvxAhREY1En2 TIqrRTjTPir5yAodzsVvueTdjVhgQhWKHlrNMUKK3hfWoeLXiLhtFTDn8jam/2pO tw8I3tWT16I= =+HRv -----END PGP SIGNATURE-----