CVE-2023-5978

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-23:16.cap_net Security Advisory The FreeBSD Project Topic: Incorrect libcap_net limitation list manipulation Category: core Module: libcap_net Announced: 2023-11-08 Credits: Shawn Webb, Mariusz Zaborski Affects: FreeBSD 13.2 and later Corrected: 2023-11-06 19:19:04 UTC (stable/14, 14.0-STABLE) 2023-11-08 00:45:34 UTC (releng/14.0, 14.0-RC4-p1) 2023-11-06 19:19:54 UTC (stable/13, 13.2-STABLE) 2023-11-08 00:49:31 UTC (releng/13.2, 13.2-RELEASE-p5) CVE Name: CVE-2023-5978 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background libcasper(3) allows Capsicum-sandboxed applications to define and use system interfaces which would otherwise be disallowed, through implementing special services. One of these services, libcap_net, enables networking capabilities within the restriced environment. II. Problem Description Casper services allow limiting operations that a process can perform. Each service maintains a specific list of permitted operations. Certain operations can be further restricted, such as specifying which domain names can be resolved. During the verification of limits, the service must ensure that the new set of constraints is a subset of the previous one. In the case of the cap_net service, the currently limited set of domain names was fetched incorrectly. III. Impact In certain scenarios, if only a list of resolvable domain names was specified without setting any other limitations, the application could submit a new list of domains including include entries not previously in the list. IV. Workaround No workaround is available. Note that no FreeBSD base system software is vulnerable to this issue. 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 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. # fetch https://security.FreeBSD.org/patches/SA-23:16/cap_net.patch # fetch https://security.FreeBSD.org/patches/SA-23:16/cap_net.patch.asc # gpg --verify cap_net.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 . Restart all daemons that use the library, or 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/14/ 765757c6301f stable/14-n265696 releng/14.0/ 5f4fc91cc87c releng/14.0-n265377 stable/13/ 114c6d9bef76 stable/13-n256672 releng/13.2/ acd860c3622d releng/13.2-n254640 - ------------------------------------------------------------------------- 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 VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEthUnfoEIffdcgYM7bljekB8AGu8FAmVLKaYACgkQbljekB8A Gu8Ofg/6AxzPey7hIS6rRO5Mv5ufiKEiYDwPo3t6epUiaLid21KhkLry1CofqFHd pC0zsYDJiWCkvieGBHhCkNYmffL9TCgLqNxSSH7plwMHwrLLQKxYRVn9V0ReGdc9 qRY5XB1W0Ocns0CbpEXuMRNde5UNwc63xN0/xlnBESfex6+fP9kPNB7VLoYY4Foj jDzn6s8YNaUOVO7YtlZDjPRRazwVLriQ3Bf+lCNkJFq4VyyhRPFkeknOFHt5olA2 dp+DIVQGUVRGjeaZDlxLZ4j0Nw39ZK8T6mSXSskjtSfQtHd6DPgDFBzZKjhtzRFd +5lutnrXpZemQjUcOKqVG1ZmlbDQChIWVlJ1kyORRjb8ZO+vknhFo/w3a5o4sq1A ZtK1w2CFo0+jL+oWxJdFEiRFR0jwMtVfMCzZAoLsDXnYbmni/353BKGMlBFgdsAy Php3E/LsxCoFaZ+r87Z6O2UefEYMCr1FDM99SQkU1Ui3kzWEskHEvPR6JS31Htu2 9ry3c4T08r1Qhp7J9Zdfnwvtd0fyEWn16ewzeiV4M6+gPErWZncar+86b87IRKof bTJ4XiK7kcORyD5ksgcBINUd5njOvXGIYTfkqSmlyikAhnoM7MN3npUGyRq6KQTE NPAr3gWrch7pegBVP3JuDQaYwfJarg6BmPb9sWWfkzQHRf9pfOI= =XNt1 -----END PGP SIGNATURE-----