Updated Kerberos packages for Red Hat Linux 9 fix a number of vulnerabilities found in MIT Kerberos.
Kerberos is a network authentication system. The MIT Kerberos team released an advisory describing a number of vulnerabilities that affect the kerberos packages shipped as part of Red Hat Linux 9. These issues include: Vulnerabilities have been found in the triple-DES key support found in the implementation of the Kerberos IV authentication protocol included in MIT Kerberos. The Common Vulnerabilities and Exposures project has assigned the name CAN-2003-0139 to this issue. Vulnerabilities have been found in the Kerberos IV authentication protocol which allow an attacker with knowledge of a cross-realm key, which is shared with another realm, to impersonate any principal in that realm to any service in that realm. This vulnerability can only be closed by disabling cross-realm authentication in Kerberos IV (CAN-2003-0138). Vulnerabilities have been found in the RPC library used by the kadmin service in Kerberos 5. A faulty length check in the RPC library exposes kadmind to an integer overflow which can be used to crash kadmind (CAN-2003-0028). The Key Distribution Center (KDC) allows remote, authenticated attackers to cause a denial of service (crash) on KDCs within the same realm via a certain protocol request that causes the KDC to corrupt its heap (CAN-2003-0082). All users of Kerberos are advised to upgrade to these errata packages, which disable cross-realm authentication by default for Kerberos IV and which contain patches that correct these issues.