-----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-01:60 Security Advisory FreeBSD, Inc. Topic: Multiple vulnerabilities in procmail signal handling Category: ports Module: procmail Announced: 2001-09-24 Credits: Philip A. Guenther Affects: Ports collection prior to the correction date. Corrected: 2001-06-29 06:46:38 2001 UTC FreeBSD only: NO I. Background procmail is an incoming mail processor, typically used to implement mail filters as well as sorting incoming mail into folders. II. Problem Description procmail versions prior to procmail 3.20 performed unsafe actions while in the signal handlers. If a signal is delivered while procmail is already in an unsafe signal handler, undefined behaviour may result, possibly leading to the ability to perform actions as the superuser under unprivileged local user control. The procmail 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 5900 third-party applications in a ready-to-install format. The ports collection shipped with FreeBSD 4.4 is not vulnerable to this problem since it was discovered before its release. 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 Because procmail runs setuid root, a local attacker may be able to take advantage of these problems in order to obtain superuser privileges, although there are no known exploits as of the date of this advisory. IV. Workaround 1) Deinstall the procmail port/package if you have it installed. V. Solution The port procmail-3.20 and later versions include fixes for these vulnerabilities. 1) Upgrade your entire ports collection and rebuild the procmail 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/mail/procmail-3.21.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/mail/procmail-3.21.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. Path Revision - ------------------------------------------------------------------------- ports/mail/procmail/Makefile 1.38 ports/mail/procmail/distinfo 1.11 - ------------------------------------------------------------------------- VII. References -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBO6+biVUuHi5z0oilAQHoEgP9HCVVpBp0+sTfJR5ATE2B5rVCLk6qQZVC oGsQ2Xr5pm6JZfcFM4iuSPqdd8weosX6l1g81uyBTM7aHvae5ul+iQLNkFyW2CeI 98lGEa2pWV9Qw7/c19/nUSHwTGr++9XtUGysfnpI/zSQqGjkcNJF3gVe4Hsn153Q wJ5Y519JoC4= =Ti/S -----END PGP SIGNATURE-----