MIT Kerberos 5: Arbitrary remote code execution

Background

MIT Kerberos 5 is a suite of applications that implement the Kerberos network protocol.

Description

The Kerberos telnet daemon fails to properly handle usernames allowing unauthorized access to any account (CVE-2007-0956). The Kerberos administration daemon, the KDC and possibly other applications using the MIT Kerberos libraries are vulnerable to the following issues. The krb5_klog_syslog function from the kadm5 library fails to properly validate input leading to a stack overflow (CVE-2007-0957). The GSS-API library is vulnerable to a double-free attack (CVE-2007-1216).

Impact

By exploiting the telnet vulnerability a remote attacker may obtain access with root privileges. The remaining vulnerabilities may allow an authenticated remote attacker to execute arbitrary code with root privileges.

Workaround

There is no known workaround at this time.

Resolution

All MIT Kerberos 5 users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-crypt/mit-krb5-1.5.2-r1"