==========================================================================
Ubuntu Security Notice USN-5675-1
October 13, 2022

heimdal vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

Several security issues were fixed in Heimdal.

Software Description:
- heimdal: Heimdal Kerberos Network Authentication Protocol

Details:

Isaac Boukris and Andrew Bartlett discovered that Heimdal's KDC was
not properly performing checksum algorithm verifications in the
S4U2Self extension module. An attacker could possibly use this issue
to perform a machine-in-the-middle attack and request S4U2Self
tickets for any user known by the application. This issue only
affected Ubuntu 14.04 ESM, Ubuntu 16.04 ESM and Ubuntu 18.04 LTS.
(CVE-2018-16860)

It was discovered that Heimdal was not properly handling the
verification of key exchanges when an anonymous PKINIT was being
used. An attacker could possibly use this issue to perform a
machine-in-the-middle attack and expose sensitive information.
This issue only affected Ubuntu 14.04 ESM, Ubuntu 16.04 ESM and
Ubuntu 18.04 LTS. (CVE-2019-12098)

Joseph Sutton discovered that Heimdal was not properly handling
memory management operations when dealing with TGS-REQ tickets that
were missing information. An attacker could possibly use this issue
to cause a denial of service. (CVE-2021-3671)

Michał Kępień discovered that Heimdal was not properly handling
logical conditions that related to memory management operations. An
attacker could possibly use this issue to cause a denial of service.
(CVE-2022-3116)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS:
   heimdal-clients                 7.7.0+dfsg-1ubuntu1.1
   heimdal-kcm                     7.7.0+dfsg-1ubuntu1.1
   heimdal-kdc                     7.7.0+dfsg-1ubuntu1.1
   heimdal-servers                 7.7.0+dfsg-1ubuntu1.1
   libgssapi3-heimdal              7.7.0+dfsg-1ubuntu1.1
   libkdc2-heimdal                 7.7.0+dfsg-1ubuntu1.1
   libkrb5-26-heimdal              7.7.0+dfsg-1ubuntu1.1

Ubuntu 18.04 LTS:
   heimdal-clients                 7.5.0+dfsg-1ubuntu0.1
   heimdal-kcm                     7.5.0+dfsg-1ubuntu0.1
   heimdal-kdc                     7.5.0+dfsg-1ubuntu0.1
   heimdal-servers                 7.5.0+dfsg-1ubuntu0.1
   libgssapi3-heimdal              7.5.0+dfsg-1ubuntu0.1
   libkdc2-heimdal                 7.5.0+dfsg-1ubuntu0.1
   libkrb5-26-heimdal              7.5.0+dfsg-1ubuntu0.1

Ubuntu 16.04 ESM:
   heimdal-clients 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1
   heimdal-kcm 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1
   heimdal-kdc 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1
   heimdal-servers 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1
   libgssapi3-heimdal 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1
   libkdc2-heimdal 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1
   libkrb5-26-heimdal 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1

Ubuntu 14.04 ESM:
   heimdal-clients 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   heimdal-clients-x 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   heimdal-kcm 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   heimdal-kdc 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   heimdal-servers 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   heimdal-servers-x 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   libgssapi3-heimdal 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   libkdc2-heimdal 1.6~git20131207+dfsg-1ubuntu1.2+esm1
   libkrb5-26-heimdal 1.6~git20131207+dfsg-1ubuntu1.2+esm1

After a standard system update you need to restart any application
using Heimdal libraries to make all the necessary changes.

References:
   https://ubuntu.com/security/notices/USN-5675-1
   CVE-2018-16860, CVE-2019-12098, CVE-2021-3671, CVE-2022-3116

Package Information:
https://launchpad.net/ubuntu/+source/heimdal/7.7.0+dfsg-1ubuntu1.1
https://launchpad.net/ubuntu/+source/heimdal/7.5.0+dfsg-1ubuntu0.1