FreeBSD Security Advisory FreeBSD-SA-20:27.ure
15 September, 2020 by firstname.lastname@example.org | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:27.ure Security Advisory The FreeBSD Project Topic: ure device driver susceptible to packet-in-packet attack Category: core Module: ure Announced: 2020-09-15 Credits: John-Mark Gurney Affects: All supported versions of FreeBSD. Corrected: 2020-09-14 19:39:43 UTC (stable/12, 12.2-STABLE) 2020-09-15 21:42:05 UTC (releng/12.2, 12.2-BETA1-p1) 2020-09-15 21:42:05 UTC (releng/12.1, 12.1-RELEASE-p10) 2020-09-15 00:22:30 UTC (stable/11, 11.4-STABLE) 2020-09-15 21:42:05 UTC (releng/11.4, 11.4-RELEASE-p4) 2020-09-15 21:42:05 UTC (releng/11.3, 11.3-RELEASE-p14) CVE Name: CVE-2020-7464 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 The ure(4) driver provides support for USB Ethernet adapters based on the Realtek RTL8152 and RTL8153 USB Ethernet controllers. II. Problem Description A programming error in the ure(4) device driver caused some Realtek USB Ethernet interfaces to incorrectly report packets with more than 2048 bytes in a single USB transfer as having a length of only 2048 bytes. An adversary can exploit this to cause the driver to misinterpret part of the payload of a large packet as a separate packet, and thereby inject packets across security boundaries such as VLANs. III. Impact An attacker that can send large frames (larger than 2048 bytes in size) to be received by the host (be it VLAN, or non-VLAN tagged packet), can inject arbitrary packets to be received and processed by the host. This includes spoofing packets from other hosts, or injecting packets to other VLANs than the host is on. IV. Workaround No workaround is available. However, an attacker needs to be able to inject large frames. If a switch can prevent large frames (>2048 bytes) from being received, or connecting the machine to a switch that does not forward large frames will mitigate this attack. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date, and reboot. 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 # shutdown -r +10min "Rebooting for a security update" 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. [FreeBSD 12.1, FreeBSD 12.2] # fetch https://security.FreeBSD.org/patches/SA-20:27/ure.12.patch # fetch https://security.FreeBSD.org/patches/SA-20:27/ure.12.patch.asc # gpg --verify ure.12.patch.asc [FreeBSD 11.3, FreeBSD 11.4] # fetch https://security.FreeBSD.org/patches/SA-20:27/ure.11.patch # fetch https://security.FreeBSD.org/patches/SA-20:27/ure.11.patch.asc # gpg --verify ure.11.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile your kernel as described in <URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/12/ r365730 releng/12.2/ r365778 releng/12.1/ r365778 stable/11/ r365738 releng/11.4/ r365778 releng/11.3/ r365778 - ------------------------------------------------------------------------- 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-2020-7464> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:27.ure.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl9hOIxfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cJY9A//Z+Rt20iUnM79er+CYF4EQNrzR8dOKr2/6L5ho5L1kJt0MdZtamN+f5Bq Jpzem060oAv+0mgAiK3VR7unlkEk+wFNvMwhgItvI8l2TME3+n/A0nsYQkP9QPPp SwHmKcIAbwkdtv913zy7AGc/vE+2+D8x84WHp6WDhRmDVgU5QAPGgP4yv0qhgkpy L8ndLDte3tXMk0eWArxWTpMfxqKGmp9Cgy88QRoIpguazS+ocSVt6h3emxQPtTc/ 7SQOEqjg4IiEXW/t2SSDqB1cvNPmN82yJt4mQg1m8v/SjFjFQ2qgFC+47cYezI1F nLuoDw16kYUu65DyePiXfCsBwSjkLU1IgpBSgmmxjMzwoVgE7/9AtRqiCwe2xkEF E6c1VWAQAw2AiZmsISv8T9RNLegLnNjyhO9iSsaeuOfLbTIeQ9zbcUL6xgZB6AxO tk/fkt+NHwuRoXNx2SC959r+hwhdnrpgxTEphjCFuuMdMGKsxm3TQGdwD6ZvQ1r2 HkVV1m4ukgpxw8ONa88Lgo+2f1HZhZKWLzp3EsTA3LMpgk+5uJjIuL/ctuddscWY Do9VapPTIGxjZqABGtxJL7NrzCz2pXE0CHzAjFWD830kujgcdihe6FbJx0cJe3m8 +CxaGBXvSINHyPwgDArnKR3Hrd57/T6RSUWqsksB7fBCpmFdQaI= =S9sW -----END PGP SIGNATURE----- _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "firstname.lastname@example.org"