CVE-2023-5368

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-23:12.msdosfs Security Advisory The FreeBSD Project Topic: msdosfs data disclosure Category: core Module: msdosfs (FAT) file system driver Announced: 2023-10-03 Credits: Maxim Suhanov Affects: All supported versions of FreeBSD. Corrected: 2023-07-18 05:46:13 UTC (stable/13, 13.2-STABLE) 2023-10-03 21:23:40 UTC (releng/13.2, 13.2-RELEASE-p4) 2023-09-11 18:51:21 UTC (stable/12, 12.4-STABLE) 2023-10-03 22:15:40 UTC (releng/12.4, 12.4-RELEASE-p6) CVE Name: CVE-2023-5368 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background The msdosfs driver provides read and write access to MS-DOS (FAT) file systems. Systems may be configured to allow unprivileged users to have read and write access to mounted msdosfs file systems. II. Problem Description In certain cases using the truncate or ftruncate system call to extend a file size populates the additional space in the file with unallocated data from the underlying disk device, rather than zero bytes. III. Impact A user with write access to files on a msdosfs file system may be able to read unintended data (for example, from a previously deleted file). 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, 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 amd64, i386, or (on FreeBSD 13 and later) arm64 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 13.2] # fetch https://security.FreeBSD.org/patches/SA-23:12/msdosfs.13.2.patch # fetch https://security.FreeBSD.org/patches/SA-23:12/msdosfs.13.2.patch.asc # gpg --verify msdosfs.13.2.patch.asc [FreeBSD 12.4] # fetch https://security.FreeBSD.org/patches/SA-23:12/msdosfs.12.4.patch # fetch https://security.FreeBSD.org/patches/SA-23:12/msdosfs.12.4.patch.asc # gpg --verify msdosfs.12.4.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 and reboot the system. VI. Correction details This issue is corrected by the corresponding Git commit hash or Subversion revision number in the following stable and release branches: Branch/path Hash Revision - ------------------------------------------------------------------------- stable/13/ 868f3eadc5e0 stable/13-n255824 releng/13.2/ 7d08a7e6908b releng/13.2-n254635 stable/12/ r373207 releng/12.4/ r373233 - ------------------------------------------------------------------------- For FreeBSD 13 and later: Run the following command to see which files were modified by a particular commit: # git show --stat Or visit the following URL, replacing NNNNNN with the hash: To determine the commit count in a working tree (for comparison against nNNNNNN in the table above), run: # git rev-list --count --first-parent HEAD For FreeBSD 12 and earlier: Run the following command to see which files were modified by a particular revision, replacing NNNNNN with the revision number: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEthUnfoEIffdcgYM7bljekB8AGu8FAmUclUoACgkQbljekB8A Gu9CSw/9G+9cwxNruCQaEOcNGCIUdOe9itmZzVJKVtIIWqXZhq+unXRS0D2YDMdA EKkfGj6GYaPnFlRe7T3cfrqUFhlNMb4Na5SW0wJp8HUqhKzKB4/SNZSs+iXNQE2z WdhYFl582Gg2+vuoije4Z9Idl0WYPqXHXyRC7TCtSwUHDwRsU9jA6g/GNM0X+0dl mOzFxFSSGoORF5aJYtp91KeNwGdNwORc75k6xxMWGGDc0sba9Fbupfrjc/XQ8SaQ tYil3Eomh/cbYOKneppGQo9ohY+PAC1u/2XxRBxXYFCDtNLed4SGEWp4pLKjq2QM X8jkDooTPLwDiVaM6Cps54PmUI3YBrYKSpt3Z1SdTHWyh0hDtpAJb/1f/sPUu90D oWCiFI5p6oZjFNJxskZZ8T6xFgjqiII70ULfHQ3GxGhMZ0Pe5QyzmqIFGvkn0UtX uGechgeL+jwqnyviIFyfVTGORmbcWj60WHajUAVUbb5aF/WV5QS0XDOLhTFkeY/P WQjOBFAH/pf93ahUnA0NuDqAe5yX/3NEXLzMg8bnSBDJRIPRWsPfIE3lqWl0zNmD sdtsugBS74zTM3MUn/Lq5MdtozuvEWK6Hs60i1wuiTMT39X8oE89r5LLVgTyc0Tj 2nML+7TKutMqWgeRvYsXBp6VtEiZd9Qc6nx8FWtSq8UMODa57C8= =T0YO -----END PGP SIGNATURE-----