USN-5828-1: Kerberos vulnerabilities

Publication date

25 January 2023

Overview

Several security issues were fixed in Kerberos.


Packages

  • krb5 - MIT Kerberos Network Authentication Protocol

Details

It was discovered that Kerberos incorrectly handled certain S4U2Self
requests. An attacker could possibly use this issue to cause a denial of
service. This issue was only addressed in Ubuntu 16.04 ESM and Ubuntu
18.04 LTS. (CVE-2018-20217)

Greg Hudson discovered that Kerberos PAC implementation incorrectly
handled certain parsing operations. A remote attacker could use this
issue to cause a denial of service, or possibly execute arbitrary code.
(CVE-2022-42898)

It was discovered that Kerberos incorrectly handled certain S4U2Self
requests. An attacker could possibly use this issue to cause a denial of
service. This issue was only addressed in Ubuntu 16.04 ESM and Ubuntu
18.04 LTS. (CVE-2018-20217)

Greg Hudson discovered that Kerberos PAC implementation incorrectly
handled certain parsing operations. A remote attacker could use this
issue to cause a denial of service, or possibly execute arbitrary code.
(CVE-2022-42898)

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
22.10 kinetic krb5-user –  1.20-1ubuntu0.1
libkdb5-10 –  1.20-1ubuntu0.1
libgssapi-krb5-2 –  1.20-1ubuntu0.1
krb5-kdc –  1.20-1ubuntu0.1
krb5-admin-server –  1.20-1ubuntu0.1
22.04 jammy krb5-user –  1.19.2-2ubuntu0.1
libkdb5-10 –  1.19.2-2ubuntu0.1
libgssapi-krb5-2 –  1.19.2-2ubuntu0.1
krb5-kdc –  1.19.2-2ubuntu0.1
krb5-admin-server –  1.19.2-2ubuntu0.1
20.04 focal libkdb5-9 –  1.17-6ubuntu4.2
krb5-user –  1.17-6ubuntu4.2
libgssapi-krb5-2 –  1.17-6ubuntu4.2
krb5-kdc –  1.17-6ubuntu4.2
krb5-admin-server –  1.17-6ubuntu4.2
18.04 bionic libkdb5-9 –  1.16-2ubuntu0.3
krb5-user –  1.16-2ubuntu0.3
libgssapi-krb5-2 –  1.16-2ubuntu0.3
krb5-kdc –  1.16-2ubuntu0.3
krb5-admin-server –  1.16-2ubuntu0.3
16.04 xenial krb5-user –  1.13.2+dfsg-5ubuntu2.2+esm3  
libgssapi-krb5-2 –  1.13.2+dfsg-5ubuntu2.2+esm3  
krb5-kdc –  1.13.2+dfsg-5ubuntu2.2+esm3  
libkdb5-8 –  1.13.2+dfsg-5ubuntu2.2+esm3  
krb5-admin-server –  1.13.2+dfsg-5ubuntu2.2+esm3  
14.04 trusty krb5-user –  1.12+dfsg-2ubuntu5.4+esm3  
libgssapi-krb5-2 –  1.12+dfsg-2ubuntu5.4+esm3  
krb5-kdc –  1.12+dfsg-2ubuntu5.4+esm3  
libkdb5-7 –  1.12+dfsg-2ubuntu5.4+esm3  
krb5-admin-server –  1.12+dfsg-2ubuntu5.4+esm3  

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.


Have additional questions?

Talk to a member of the team ›