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

  • FreeBSD Security Advisory FreeBSD-SA-24:01.bhyveload

    From FreeBSD Security Advisories@21:1/5 to All on Wed Feb 14 08:00:06 2024
    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA512

    ============================================================================= FreeBSD-SA-24:01.bhyveload Security Advisory
    The FreeBSD Project

    Topic: bhyveload(8) host file access

    Category: core
    Module: bhyeload
    Announced: 2024-02-14
    Credits: The water cooler. (Note, this is the requested credit)
    Affects: All supported versions of FreeBSD.
    Corrected: 2024-01-15 22:27:59 UTC (stable/14, 14.0-STABLE)
    2024-02-14 06:05:44 UTC (releng/14.0, 14.0-RELEASE-p5)
    2024-01-15 23:11:38 UTC (stable/13, 13.2-STABLE)
    2024-02-14 06:06:00 UTC (releng/13.2, 13.2-RELEASE-p10)
    CVE Name: CVE-2024-25940

    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

    bhyveload(8) is used to load a FreeBSD guest into a bhyve virtual machine.

    II. Problem Description

    `bhyveload -h <host-path>` may be used to grant loader access to the <host-path>
    directory tree on the host. Affected versions of bhyveload(8) do not make any attempt to restrict loader's access to <host-path>, allowing the loader to read any file the host user has access to.

    III. Impact

    In the bhyveload(8) model, the host supplies a userboot.so to boot with, but the
    loader scripts generally come from the guest image. A maliciously crafted script could be used to exfiltrate sensitive data from the host accessible to the user running bhyhveload(8), which is often the system root.

    IV. Workaround

    No workaround is available, but guests that do not use `bhyveload -h` are not impacted. Common VM solutions that use bhyveload(8) do not usually use the
    - -h option.

    V. Solution

    Upgrade your 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

    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 14.0]
    # fetch https://security.FreeBSD.org/patches/SA-24:01/bhyveload-14.0.patch
    # fetch https://security.FreeBSD.org/patches/SA-24:01/bhyveload-14.0.patch.asc # gpg --verify bhyveload-14.0.patch.asc

    [FreeBSD 13.2]
    # fetch https://security.FreeBSD.org/patches/SA-24:01/bhyveload-13.2.patch
    # fetch https://security.FreeBSD.org/patches/SA-24:01/bhyveload-13.2.patch.asc # gpg --verify bhyveload-13.2.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>. Virtual machines that have been booted with bhyveload(8) do not need to be rebooted.

    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/ 426b28fdf700 stable/14-n266333 releng/14.0/ f5bb597829e1 releng/14.0-n265406 stable/13/ 78345dbd7a00 stable/13-n257186 releng/13.2/ 48598b1670ce releng/13.2-n254657
    - -------------------------------------------------------------------------

    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://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-25940>

    The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-24:01.bhyveload.asc> -----BEGIN PGP SIGNATURE-----

    iQIzBAEBCgAdFiEEthUnfoEIffdcgYM7bljekB8AGu8FAmXMYRAACgkQbljekB8A Gu8KwRAAxCnMsCQbp/CZ1O2GYxDTCOt1M5CZaFBD8r3b4xSN1gFB79z3aHAmSX0a kTGpp5QSbxx1UtA9eZoZTa/wpmMAo1AZ7ry0OK1VuRFtF2D+IM64l07m91HW5ncU YCsbeQ6wuXHeVlZ/t7eu/X03YltYIuMu/wIzpsPYtMvTB+ZI50nm0pUGaQnH9ZA2 jMGhLcWQSaHi46pMJ1o2iXWbaFZh4S6fHhNXSEFxaWuQf/o//whSgeqtFnhozfZ4 vbx0pyF3HrkjPRLwc9QDRNcFnG0F9DCOmiGlAAZD4/XRNOd5PgSvmHxDPrc1UkJO K8CcU7vIgloKdETS43HhlDhT34/adV1dMpwCLpr9JZ3FmfTtIor1q8w9l0nLohln VeLUbhaMZAXYqQp5wcDso26n9moD8l/izJZZ0gWu8xsooKmE2DY0t7ASXdcvnSq8 VKlpZP0DHcdZdeePiCF6XovAvv3fAq5hvIdCccBIJHbFIWEL2Psq9hYqFISb+mFb gAoX5gyo4S+lWgn33aUCzjYuR0MhelJPRFIndjr5+Dn0AgQniNre7uRt4k97jvT1 Q9h+f4uyNFafuD5YMqfRhsk8EN93bEc3Bkq47KCYDSTJujd99pYFPE1SzvNAPmNY CYxqYjkfjklarfellifxvqdKrOWoeOkK4a3Ckd5+4Y8BaaTzWCY=
    =LOMD
    -----END PGP SIGNATURE-----

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