USN-940-1: Kerberos vulnerabilities

Ubuntu Security Notice USN-940-1

19th May, 2010

krb5 vulnerabilities

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

  • Ubuntu 9.10
  • Ubuntu 9.04
  • Ubuntu 8.04 LTS
  • Ubuntu 6.06 LTS

Summary

Unauthenticated remote attackers could cause Kerberos servers to crash, leading to a denial of service.

Software description

  • krb5 - MIT Kerberos authentication services

Details

It was discovered that Kerberos did not correctly free memory in the
GSSAPI and kdb libraries. If a remote attacker were able to manipulate
an application using these libraries carefully, the service could
crash, leading to a denial of service. (Only Ubuntu 6.06 LTS was
affected.) (CVE-2007-5902, CVE-2007-5971, CVE-2007-5972)

Joel Johnson, Brian Almeida, and Shawn Emery discovered that Kerberos
did not correctly verify certain packet structures. An unauthenticated
remote attacker could send specially crafted traffic to cause the KDC or
kadmind services to crash, leading to a denial of service. (CVE-2010-1320,
CVE-2010-1321)

Update instructions

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

Ubuntu 9.10:
krb5-admin-server 1.7dfsg~beta3-1ubuntu0.6
krb5-kdc 1.7dfsg~beta3-1ubuntu0.6
Ubuntu 9.04:
krb5-admin-server 1.6.dfsg.4~beta1-5ubuntu2.4
krb5-kdc 1.6.dfsg.4~beta1-5ubuntu2.4
Ubuntu 8.04 LTS:
krb5-admin-server 1.6.dfsg.3~beta1-2ubuntu1.5
krb5-kdc 1.6.dfsg.3~beta1-2ubuntu1.5
Ubuntu 6.06 LTS:
libkrb53 1.4.3-5ubuntu0.11
krb5-kdc 1.4.3-5ubuntu0.11

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

In general, a standard system update will make all the necessary changes.

References

CVE-2007-5902, CVE-2007-5971, CVE-2007-5972, CVE-2010-1320, CVE-2010-1321