ESB-2017.1741 - [FreeBSD] heimdal: Multiple vulnerabilities 2017-07-13

Printable version
PGP/GPG verifiable version

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.1741
           heimdal KDC-REP service name validation vulnerability
                               13 July 2017

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           heimdal
Publisher:         FreeBSD
Operating System:  FreeBSD
Impact/Access:     Access Privileged Data         -- Remote/Unauthenticated
                   Provide Misleading Information -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-11103  

Original Bulletin: 
   https://security.freebsd.org/advisories/FreeBSD-SA-17:05.heimdal.asc

- --------------------------BEGIN INCLUDED TEXT--------------------

- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

=============================================================================
FreeBSD-SA-17:05.heimdal                                    Security Advisory
                                                          The FreeBSD Project

Topic:          heimdal KDC-REP service name validation vulnerability

Category:       contrib
Module:         heimdal
Announced:      2017-07-12
Affects:        All supported versions of FreeBSD.
Corrected:      2017-07-12 07:26:07 UTC (stable/11, 11.1-PRERELEASE)
                2017-07-12 08:07:16 UTC (releng/11.1, 11.1-RC2-p1)
                2017-07-12 08:07:16 UTC (releng/11.1, 11.1-RC1-p1)
                2017-07-12 07:26:07 UTC (stable/11, 11.1-BETA3-p1)
                2017-07-12 08:07:36 UTC (releng/11.0, 11.0-RELEASE-p11)
                2017-07-12 07:26:07 UTC (stable/10, 10.3-STABLE)
                2017-07-12 15:16:01 UTC (releng/10.3, 10.3-RELEASE-p20)
CVE Name:       CVE-2017-11103

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

Heimdal implements the Kerberos 5 network authentication protocols.
The Kerberos protocol uses "tickets" to authenticate a client to a
service.

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
principal.

II.  Problem Description

There is a programming error in the Heimdal implementation that used an
unauthenticated, plain-text version of the KDC-REP service name found
in a ticket.

III. Impact

An attacker who has control of the network between a client and the
service it talks to will be able to impersonate the service, allowing
a successful man-in-the-middle (MITM) attack that circumvents the mutual
authentication.

IV.  Workaround

No workaround is available, but only Kerberos enabled clients are
affected.

V.   Solution

Perform one of the following:

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

A reboot is recommended.

2) To update your vulnerable system via a binary patch:

Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

A reboot is recommended.

3) 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-17:05/heimdal.patch
# fetch https://security.FreeBSD.org/patches/SA-17:05/heimdal.patch.asc
# 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:https://www.FreeBSD.org/handbook/makeworld.html>.

Restart all daemons that use the library, or reboot the system.

VI.  Correction details

The following list contains the correction revision numbers for each
affected branch.

Branch/path                                                      Revision
- - -------------------------------------------------------------------------
stable/10/                                                        r320907
releng/10.3/                                                      r320915
stable/11/                                                        r320907
releng/11.0/                                                      r320911
releng/11.1/                                                      r320910
- - -------------------------------------------------------------------------

To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:

# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base

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

<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>

VII. References

<URL:https://www.orpheus-lyre.info/>

<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-11103>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-17:05.heimdal.asc>
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.1.21 (FreeBSD)
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=QQ1C
- -----END PGP SIGNATURE-----

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iQIVAwUBWWb9hYx+lLeg9Ub1AQhb4g/9FbHGvKOHN5lLGqUyaLlh2L2vRyIj7jeS
R7gFLRxstNvq75xBJeBx1RPptIzV+DBaAigLrrhKu1LGPRUwBFw/FuGnLg7+0psK
/X2/wGVpVMZyfUvKia6CXszde0PyAdzm1WVrspAuIkB6eRUzPm/qA4Pj6ho+eSOq
+498K/k9D372b/Tz8RnbnVAWw4BN5dchFk9Sa8OldSPfDg64ZsUZlD6namedEObu
TVFBtAwGmfYdPVPqASsbEEXcfZ621Y9gTdWzXFdkLwV7J/xeSDWuOslawz4KqHKr
LoANXnIjqnZogUW8peysUuwsBzCdWPZOEPsTJzYaIVJzP3oWVzhnDzvFzC+R25FH
bVh++p350HZdrMhQLP04L/E/hB7GbtwcRIFkTEI2kh6bnUA/wPIIjeEs4zMeuEFA
zWxyedk1GMZ/RNVqL4J8l8POEeRVfQ3za0UeV5IFfYRi+RAY3nYkX+l5GjZP6bXw
th5WdUqhTJtFN8dz7TDIi4srZnn9mTEZFyKRIMU9tIXyvNwL2ps5qF0oDth5W3iF
cnFrkEJYehUcRd6/FKN+MQAQsWtwPB43CqnYQO2gnWQZK/d56AA1gEdJ2O/QRd8B
sIrjvCZt2pzZ4/0mJg4lfnTLJjz+EIgUibdQgQT29W9ulmZbI4F2QbYAYwrsVJyZ
xnTkQvB4A6E=
=T8dB
-----END PGP SIGNATURE-----

« Back to bulletins