Ubuntu: 1520-1: Kerberos vulnerabilities
Posted by Benjamin D. Thomas   
Ubuntu Several security issues were fixed in Kerberos.
==========================================================================
Ubuntu Security Notice USN-1520-1
July 31, 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 versions:

Ubuntu 12.04 LTS:
  krb5-admin-server               1.10+dfsg~beta1-2ubuntu0.3
  krb5-kdc                        1.10+dfsg~beta1-2ubuntu0.3
  krb5-kdc-ldap                   1.10+dfsg~beta1-2ubuntu0.3

Ubuntu 11.10:
  krb5-admin-server               1.9.1+dfsg-1ubuntu2.3
  krb5-kdc                        1.9.1+dfsg-1ubuntu2.3
  krb5-kdc-ldap                   1.9.1+dfsg-1ubuntu2.3

Ubuntu 11.04:
  krb5-admin-server               1.8.3+dfsg-5ubuntu2.3
  krb5-kdc                        1.8.3+dfsg-5ubuntu2.3
  krb5-kdc-ldap                   1.8.3+dfsg-5ubuntu2.3

Ubuntu 10.04 LTS:
  krb5-admin-server               1.8.1+dfsg-2ubuntu0.11
  krb5-kdc                        1.8.1+dfsg-2ubuntu0.11
  krb5-kdc-ldap                   1.8.1+dfsg-2ubuntu0.11

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

References:
  http://www.ubuntu.com/usn/usn-1520-1
  CVE-2012-1012, CVE-2012-1013, CVE-2012-1014, CVE-2012-1015

Package Information:
  https://launchpad.net/ubuntu/+source/krb5/1.10+dfsg~beta1-2ubuntu0.3
  https://launchpad.net/ubuntu/+source/krb5/1.9.1+dfsg-1ubuntu2.3
  https://launchpad.net/ubuntu/+source/krb5/1.8.3+dfsg-5ubuntu2.3
  https://launchpad.net/ubuntu/+source/krb5/1.8.1+dfsg-2ubuntu0.11