-----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-01:61 Security Advisory FreeBSD, Inc. Topic: Squid in accelerator-only mode ignores ACLs Category: ports Modules: squid22, squid23, squid24 Announced: 2001-10-08 Credits: Paul Nasrat Affects: Ports collection prior to the correction date. Corrected: 2001-07-29 12:29:00 (squid23) 2001-08-28 16:48:35 2001 UTC (squid24) FreeBSD only: NO I. Background The Squid Internet Object Cache is a web proxy/cache. II. Problem Description If squid is configured in acceleration-only mode (http_accel_host is set, but http_accel_with_proxy is off), then as a result of a bug, access control lists (ACLs) are ignored. III. Impact A remote attacker may use the squid server in order to issue requests to hosts that are otherwise inaccessible. Because the squid server processes these requests as HTTP requests, the attacker cannot send or retrieve arbitrary data. However, the attacker could use squid's response to determine if a particular port is open on a victim host. Therefore, the squid server may be used to conduct a port scan. IV. Workaround 1) Do not run squid in acceleration-only mode. 2) Deinstall the squid port/package if you have it installed. V. Solution The port squid-2.3_1 and later 2.3 versions, and the port squid-2.4_5 and later 2.4 versions include fixes for this vulnerability. The squid-2.3 and squid-2.2 ports have been deprecated and removed from the ports collection, and users are advised to upgrade to squid-2.4 as soon as possible. 1) Upgrade your entire ports collection and rebuild the squid port. 2) Deinstall the old package and install a new package dated after the correction date, obtained from the following directories: [i386] ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/www/squid-2.3_1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/www/squid-2.4_5.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/www/squid-2.3_1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/www/squid-2.4_5.tgz [alpha] Packages are not automatically generated for the alpha architecture at this time due to lack of build resources. 3) Download a new port skeleton for the procmail 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-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/portcheckout-2.0.tgz VI. Correction details The following list contains the revision numbers of each file that was corrected in the FreeBSD ports collection. Affected port Path Revision - ------------------------------------------------------------------------- squid22 *NOT CORRECTED* squid23 ports/www/squid23/Makefile 1.78 ports/www/squid23/distinfo 1.57 squid24 ports/www/squid24/Makefile 1.84 ports/www/squid24/distinfo 1.61 - ------------------------------------------------------------------------- VII. References -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBO8IVHVUuHi5z0oilAQGK1AP+MZ+Drf7VzdO1O0nr4SIIS8/FGmLYsIha WsjWUBpmIeQk/c8jjLDMu32yIRoZNSu3F1Alc4XieDznAE8ZjburLMHY9RrQHOOY WKuBcjjgSpmeB84MVIT0nCOtlI6+cmk7gLflxNYwUY1QKkIff5KrhTRqByJnICW3 +g0WZtpdinE= =js2W -----END PGP SIGNATURE-----