1. Forum
  2. Usenet
  3. COMP.UNIX.BSD.FREEBSD.ANN

  • FreeBSD Security Advisory FreeBSD-SA-24:07.nfsclient

    From FreeBSD Security Advisories@21:1/5 to All on Wed Aug 7 16:00:17 2024
    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA512

    ============================================================================= FreeBSD-SA-24:07.nfsclient Security Advisory
    The FreeBSD Project

    Topic: NFS client accepts file names containing path separators

    Category: core
    Module: NFS client
    Announced: 2024-08-07
    Credits: Apple Security Engineering and Architecture (SEAR)
    Affects: All supported versions of FreeBSD
    Corrected: 2024-07-27 03:54:45 UTC (stable/14, 14.1-STABLE)
    2024-08-07 13:44:21 UTC (releng/14.1, 14.1-RELEASE-p3)
    2024-08-07 13:44:39 UTC (releng/14.0, 14.0-RELEASE-p9)
    2024-07-28 04:14:54 UTC (stable/13, 13.3-STABLE)
    2024-08-07 13:44:52 UTC (releng/13.3, 13.3-RELEASE-p5)
    CVE Name: CVE-2024-6759

    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 Network File System (NFS) is a distributed file system that allows remote systems to access files and directories over a network as if they were local. FreeBSD includes both server and client implementations of NFS.

    II. Problem Description

    When mounting a remote filesystem using NFS, the kernel did not sanitize remotely provided filenames for the path separator character, "/". This
    allows readdir(3) and related functions to return filesystem entries with
    names containing additional path components.

    III. Impact

    The lack of validation described above gives rise to a confused deputy
    problem. For example, a program copying files from an NFS mount could be tricked into copying from outside the intended source directory, and/or to a location outside the intended destination directory.

    IV. Workaround

    No workaround is available. Note that for the problem to occur, the NFS
    server would have to deliberately inject altered paths into RPC replies, or
    a MITM would have to be altering NFS traffic.

    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 or arm64 platforms, or the i386 platform on FreeBSD 13, 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 13.3]
    # fetch https://security.FreeBSD.org/patches/SA-24:07/nfclient-13.patch
    # fetch https://security.FreeBSD.org/patches/SA-24:07/nfclient-13.patch.asc
    # gpg --verify nfsclient-13.patch.asc

    [FreeBSD 14.0 & FreeBSD 14.1]
    # fetch https://security.FreeBSD.org/patches/SA-24:07/nfclient-14.patch
    # fetch https://security.FreeBSD.org/patches/SA-24:07/nfclient-14.patch.asc
    # gpg --verify nfsclient-14.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

    This issue is corrected as of the corresponding Git commit hash in the following stable and release branches:

    Branch/path Hash Revision
    - ------------------------------------------------------------------------- stable/14/ 9328ded386d5 stable/14-n268239 releng/14.1/ 8533e927afc1 releng/14.1-n267686 releng/14.0/ 4e7bf17e9db8 releng/14.0-n265422 stable/13/ 0172b5145ad9 stable/13-n258140 releng/13.3/ 3d5cb2b9a97c releng/13.3-n257439
    - -------------------------------------------------------------------------

    Run the following command to see which files were modified by a
    particular commit:

    # git show --stat <commit hash>

    Or visit the following URL, replacing NNNNNN with the hash:

    <URL:https://cgit.freebsd.org/src/commit/?id=NNNNNN>

    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

    <URL:https://www.cve.org/CVERecord?id=CVE-2024-6759>

    The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-24:07.nfsclient.asc> -----BEGIN PGP SIGNATURE-----

    iQIzBAEBCgAdFiEEthUnfoEIffdcgYM7bljekB8AGu8FAmazha8ACgkQbljekB8A Gu80VxAAsDhdNW5FHcXEBZXbfR6fsShdWGQo8rCY1R1Buq8uhPI4bdzXCFrgUKM7 Rm5P+zfZNcTYtM0epU1Fiz2BhjsKVfKIOMIBmuMik9xMBfeHnTihKGFBZ+TFj7i8 1Kv/NE+oCn99jKZS7sZVNBvdbDMNBq4Em0vixXGRnKlEpa3r8b7niLuB0rHa97// gzIP5GvhUTsMaw3TwCAkVnZDrx+AoAU0dbLVIFf07P4mEt7StGd76C1dq4a6+3ZV s3Gqm16H8nYan5NJzpH2SIhcav4YyDuSD1eS8isyLn5bybpROdYQT7tCAfplpR2X pX0oQ8FRlslodV/wWaGNnCTNTYoSTj0jf77CM4fd8ERdKKmhC6x9zHsDyJBzH5Ku E6JlY9IvM0fL2N4KPDpNjF/U8RmNWDcxxaaou/6uohWdg977CX8uP1wfSL/4Sw6u SvqfDwwqd5BRE4KiqMFE024zgeogeJU7i21747HKs4nxWlNuPhVrWRjrarRhYlc2 M4l2te7OQMjVPtbYhO4DXnDMqNgN37Qf2srgBiAnlOpmRX5Trgj4pw6DGQlSVoWO xY8fO02xAZuRUKgNA/TEvmRVuZx0LaLkl49xQjB8DxSvggYVFbJaY2HpfjnktmN0 ZuMlcw0h/cv9UEFn3FWy0147xN/cjXjozvACmDUWhG0LdiUcnzc=
    =tJAo
    -----END PGP SIGNATURE-----

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)