-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:01.libfetch Security Advisory The FreeBSD Project Topic: libfetch buffer overflow Category: core Module: libfetch Announced: 2020-01-28 Credits: Duncan Overbruck Affects: All supported versions of FreeBSD. Corrected: 2020-01-28 18:40:55 UTC (stable/12, 12.1-STABLE) 2020-01-28 18:55:25 UTC (releng/12.1, 12.1-RELEASE-p2) 2020-01-28 18:55:25 UTC (releng/12.0, 12.0-RELEASE-p13) 2020-01-28 18:42:06 UTC (stable/11, 11.3-STABLE) 2020-01-28 18:55:25 UTC (releng/11.3, 11.3-RELEASE-p6) CVE Name: CVE-2020-7450 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:https://security.FreeBSD.org/>. I. Background libfetch(3) is a multi-protocol file transfer library included with FreeBSD and used by the fetch(1) command-line tool, pkg(8) package manager, and others. II. Problem Description A programming error allows an attacker who can specify a URL with a username and/or password components to overflow libfetch(3) buffers. III. Impact An attacker in control of the URL to be fetched (possibly via HTTP redirect) may cause a heap buffer overflow, resulting in program misbehavior or malicious code execution. IV. Workaround No workaround is available. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Perform one of the following: 1) To update your vulnerable system via a binary patch: Systems running a RELEASE version of FreeBSD on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install 2) To update your vulnerable system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. # fetch https://security.FreeBSD.org/patches/SA-20:01/libfetch.patch # fetch https://security.FreeBSD.org/patches/SA-20:01/libfetch.patch.asc # gpg --verify libfetch.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>. Restart all daemons that use the library, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/12/ r357213 releng/12.1/ r357217 releng/12.0/ r357217 stable/11/ r357214 releng/11.3/ r357217 - ------------------------------------------------------------------------- To see which files were modified by a particular revision, run the following command, replacing NNNNNN with the revision number, on a machine with Subversion installed: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-7450> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:01.libfetch.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl4whc5fFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cJw5BAAmi4Mk+an8qJB4GwfOSxWhn42GnN9/HikJwkiTNHQr7n51ANp4sHCgTYG PCo6UvCFqdIfhpBIrykI7ZwzAetCpldDdIMQFJoi5ChJ7aIcNDpiH06yLjYLgseS qSxJ+dXt6j7G2FMUWPBka8eTNBi64gT0MbyC7zFdISfJqfNy+p0WvdwYm3UsWkeR pEV+o6zL+PI3s6IsqQTQzYuyNYgoTLdvhjgNMymI+OMH8uCdBUrdItdSwSYPwVOp +8SUX47jMFNcIbBmuQ3KnPxu9fHx8JzfqpLDAkmp6hu6sXNTmIZ27mgItu4DRgWN nvd750H6fv9UCbRYOyvjeuEN8olOpZcoTAuQDtcC/z7BvKAwLC7oAYXZEiQ4pn/D MGMzlJU7fxiyIWDNJprzyrsgPAUhCC3ePyenTErB+GQKmf1fHTjLWJHN43W2tbqk kYzMwwLQa3KwOYzHPHbJt6F94b9dN30v8cgIVkvs5ivLr8eErIJAQ71PgxkgRQL1 /C301qeJvgBqLm+so0Ef6wi/D9HvCvyk6IqbQNEvOXD8RNtyqdhBO1jJ93zDVLLK ey5room7Hln/A3l5bXBzb6O3+q60U7lbxzokkAhNoe+pls6HQ50OeainXDU1dal4 HcBOCM1cnXNjXDdizqdMDvyR7ftXuBxOYeMsxY2JbT4qKjjA19M= =chN4 -----END PGP SIGNATURE-----