USN-1520-1: Kerberos vulnerabilities

Ubuntu Security Notice USN-1520-1

31st July, 2012

krb5 vulnerabilities

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

  • Ubuntu 12.04 LTS
  • Ubuntu 11.10
  • Ubuntu 11.04
  • Ubuntu 10.04 LTS

Summary

Several security issues were fixed in Kerberos.

Software description

  • krb5 - MIT Kerberos Network Authentication Protocol

Details

Emmanuel Bouillon discovered that the MIT krb5 Key Distribution Center
(KDC) daemon could free an uninitialized pointer when handling a
malformed AS-REQ message. A remote unauthenticated attacker could
use this to cause a denial of service or possibly execute arbitrary
code. (CVE-2012-1015)

Emmanuel Bouillon discovered that the MIT krb5 Key Distribution Center
(KDC) daemon could dereference an uninitialized pointer while handling
a malformed AS-REQ message. A remote unauthenticated attacker could
use this to cause a denial of service or possibly execute arbitrary
code. This issue only affected Ubuntu 12.04 LTS. (CVE-2012-1014)

Simo Sorce discovered that the MIT krb5 Key Distribution Center (KDC)
daemon could dereference a NULL pointer when handling a malformed
TGS-REQ message. A remote authenticated attacker could use this to
cause a denial of service. (CVE-2012-1013)

It was discovered that the kadmin protocol implementation in MIT krb5
did not properly restrict access to the SET_STRING and GET_STRINGS
operations. A remote authenticated attacker could use this to expose
or modify sensitive information. This issue only affected Ubuntu
12.04 LTS. (CVE-2012-1012)

Update instructions

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

Ubuntu 12.04 LTS:
krb5-admin-server 1.10+dfsg~beta1-2ubuntu0.3
krb5-kdc-ldap 1.10+dfsg~beta1-2ubuntu0.3
krb5-kdc 1.10+dfsg~beta1-2ubuntu0.3
Ubuntu 11.10:
krb5-admin-server 1.9.1+dfsg-1ubuntu2.3
krb5-kdc-ldap 1.9.1+dfsg-1ubuntu2.3
krb5-kdc 1.9.1+dfsg-1ubuntu2.3
Ubuntu 11.04:
krb5-admin-server 1.8.3+dfsg-5ubuntu2.3
krb5-kdc-ldap 1.8.3+dfsg-5ubuntu2.3
krb5-kdc 1.8.3+dfsg-5ubuntu2.3
Ubuntu 10.04 LTS:
krb5-admin-server 1.8.1+dfsg-2ubuntu0.11
krb5-kdc-ldap 1.8.1+dfsg-2ubuntu0.11
krb5-kdc 1.8.1+dfsg-2ubuntu0.11

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-2012-1012, CVE-2012-1013, CVE-2012-1014, CVE-2012-1015