1.90. krb5

Updated krb5 packages that fix multiple security issues are now available for Red Hat Enterprise Linux 3, 4, and 5, and Red Hat Enterprise Linux 4.7, 5.2, and 5.3 Extended Update Support.

This update has been rated as having critical security impact by the Red Hat Security Response Team.

Kerberos is a network authentication system which allows clients and servers to authenticate to each other using symmetric encryption and a trusted third party, the Key Distribution Center (KDC).

Multiple integer underflow flaws, leading to heap-based corruption, were found in the way the MIT Kerberos Key Distribution Center (KDC) decrypted ciphertexts encrypted with the Advanced Encryption Standard (AES) and ARCFOUR (RC4) encryption algorithms. If a remote KDC client were able to provide a specially-crafted AES- or RC4-encrypted ciphertext or texts, it could potentially lead to either a denial of service of the central KDC (KDC crash or abort upon processing the crafted ciphertext), or arbitrary code execution with the privileges of the KDC (i.e., root privileges). (CVE-2009-4212)

All krb5 users should upgrade to these updated packages, which contain a backported patch to correct these issues. All running services using the MIT Kerberos libraries must be restarted for the update to take effect.