-----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-02:01 Security Advisory FreeBSD, Inc. Topic: Directory permission vulnerability in pkg_add [REVISED] Category: core Module: pkg_install Announced: 2002-01-04 Revised: 2002-01-07 Credits: The Anarcat Affects: All versions of FreeBSD prior to the correction date. Corrected: 2001/11/22 17:40:36 UTC (4.4-STABLE aka RELENG_4) 2001/12/07 20:58:46 UTC (4.4-RELEASEp1 aka RELENG_4_4) 2001/12/07 20:57:19 UTC (4.3-RELEASEp21 aka RELENG_4_3) FreeBSD only: NO 0. Revision History v1.0 2002-01-04 Initial release v1.1 2002-01-07 Correct terminology in problem description. I. Background pkg_add is a utility program used to install software package distributions on FreeBSD systems. II. Problem Description pkg_add extracts the contents of the package to a temporary directory, then moves files from the temporary directory to their ultimate destination on the system. The temporary directory used in the extraction was created with world-searchable permissions, allowing arbitrary users to examine the contents of the package as it was being extracted. This might allow users to attack world-writable parts of the package during installation. III. Impact A local attacker may be able to modify the package contents and potentially elevate privileges or otherwise compromise the system. There are no known exploits as of the date of this advisory. IV. Workaround 1) Remove or discontinue use of the pkg_add binary until it has been upgraded. 2) When running pkg_add, create a secure temporary directory (such as /var/tmp/inst) and secure the directory permissions (chmod 700 /var/tmp/inst). Set the TMPDIR environment variable to this directory before running pkg_add. V. Solution 1) Upgrade your vulnerable FreeBSD system to 4.4-STABLE, or the RELENG_4_4 or RELENG_4_3 security branches dated after the respective correction dates. 2) FreeBSD 4.x systems prior to the correction date: The following patch has been verified to apply to FreeBSD 4.3-RELEASE, 4.4-RELEASE, and 4-STABLE dated prior to the correction date. This patch may or may not apply to older, unsupported releases of FreeBSD. Download the patch and the detached PGP signature from the following locations, and verify the signature using your PGP utility. ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:01/pkg_add.patch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:01/pkg_add.patch.asc Execute the following commands as root: # cd /usr/src # patch -p < /path/to/patch # cd /usr/src/usr.sbin/pkg_install # make depend && make all install VI. Correction details The following list contains the $FreeBSD$ revision numbers of each file that was corrected in the FreeBSD source Path Revision Branch - ------------------------------------------------------------------------- src/usr.sbin/pkg_install/lib/pen.c HEAD 1.37 RELENG_4 1.31.2.6 RELENG_4_4 1.31.2.2.2.1 RELENG_4_3 1.31.2.1.2.1 - ------------------------------------------------------------------------- VII. References -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBPDnE7VUuHi5z0oilAQHc3AP+IVLft31MShGngUPRQOQRHsNPjdqwdacj ptKjsMfGCpDRyqgIc8CoaI/Bln6VKkKS3HuOYx4pYOPY5QjBPy9JpPSJrAxP/H/N 424apgpo2eCmGcoIbCdM2RH1YYyKZANzt5igWNss1FbppvYbVwx+zZPBA4dyl9MZ 8rat83zoMAc= =g74K -----END PGP SIGNATURE-----