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FreeBSD Security Advisory FreeBSD-SA-22:14.heimdal

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FreeBSD-SA-22:14.heimdal                                    Security Advisory
                                                          The FreeBSD Project

Topic:          Multiple vulnerabilities in Heimdal

Category:       contrib
Module:         heimdal
Announced:      2022-11-15
Affects:        All supported versions of FreeBSD.
Corrected:      2022-11-15 21:15:35 UTC (stable/13, 13.1-STABLE)
                2022-11-16 01:50:27 UTC (releng/13.1, 13.1-RELEASE-p4)
                2022-11-15 21:16:56 UTC (stable/12, 12.4-STABLE)
                2022-11-16 01:47:57 UTC (releng/12.4, 12.4-RC2-p1)
                2022-11-16 01:40:21 UTC (releng/12.3, 12.3-RELEASE-p9)
CVE Name:       CVE-2019-14870, CVE-2022-3437, CVE-2022-42898,
                CVE-2022-44640, CVE-2021-44758

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:>.

I.   Background

Heimdal implements the Kerberos 5 network authentication protocols.

A Key Distribution Center (KDC) is trusted by all principals registered
in that administrative "realm" to store a secret key in confidence, of
which, the proof of knowledge is used to verify the authenticity of a

II.  Problem Description

Multiple security vulnerabilities have been discovered in the Heimdal
implementation of the Kerberos 5 network authentication protocols and KDC.

- - CVE-2022-42898 PAC parse integer overflows
- - CVE-2022-3437 Overflows and non-constant time leaks in DES{,3} and arcfour
- - CVE-2021-44758 NULL dereference DoS in SPNEGO acceptors
- - CVE-2022-44640 Heimdal KDC: invalid free in ASN.1 codec
- - CVE-2019-14870 Validate client attributes in protocol-transition
- - CVE-2019-14870 Apply forwardable policy in protocol-transition
- - CVE-2019-14870 Always lookup impersonate client in DB

III. Impact

A malicious actor with control of the network between a client and a service
using Kerberos for authentication can impersonate either the client or the
service, enabling a man-in-the-middle (MITM) attack circumventing mutual

Note that, while CVE-2022-44640 is a severe vulnerability, possibly enabling
remote code execution on other platforms, the version of Heimdal included with
the FreeBSD base system cannot be exploited in this way on FreeBSD.

IV.  Workaround

No workaround is available, but only systems using Kerberos are affected.

V.   Solution

Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.

A reboot is recommended.

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

A reboot is recommended.

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
# fetch
# gpg --verify heimdal.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:>.

Restart all daemons that use the Kerberos, 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/13/                              d0b6550173d2    stable/13-n253097
releng/13.1/                            a1e014e89282  releng/13.1-n250170
stable/12/                                                        r372752
releng/12.4/                                                      r372755
releng/12.3/                                                      r372753
- -------------------------------------------------------------------------

For FreeBSD 13 and later:

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:


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://

Or visit the following URL, replacing NNNNNN with the revision number:


VII. References



The latest revision of this advisory is available at