MIT krb5: Multiple vulnerabilities

Background

MIT krb5 is the free implementation of the Kerberos network authentication protocol by the Massachusetts Institute of Technology.

Description

The implementation of the Key Distribution Center (KDC) and the MIT krb5 library contain double-free vulnerabilities, making client programs as well as application servers vulnerable.

The ASN.1 decoder library is vulnerable to a denial of service attack, including the KDC.

Impact

The double-free vulnerabilities could allow an attacker to execute arbitrary code on a KDC host and hosts running krb524d or vulnerable services. In the case of a KDC host, this can lead to a compromise of the entire Kerberos realm. Furthermore, an attacker impersonating a legitimate KDC or application server can potentially execute arbitrary code on authenticating clients.

An attacker can cause a denial of service for a KDC or application server and clients, the latter if impersonating a legitimate KDC or application server.

Workaround

There is no known workaround at this time.

Resolution

All mit-krb5 users should upgrade to the latest stable version:

 # emerge sync

 # emerge -pv ">=app-crypt/mit-krb5-1.3.4"
 # emerge ">=app-crypt/mit-krb5-1.3.4"