Several vulnerabilities have been discovered in krb5, an implementation of MIT Kerberos.
Kerberos version 5 does not contain this cryptographic vulnerability. Sites are not vulnerable if they have Kerberos v4 completely disabled, including the disabling of any krb5 to krb4 translation services.
This version of the krb5 package changes the default behavior and disallows cross-realm authentication for Kerberos version 4. Because of the fundamental nature of the problem, cross-realm authentication in Kerberos version 4 cannot be made secure and sites should avoid its use. A new option (-X) is provided to the krb5kdc and krb524d commands to re-enable version 4 cross-realm authentication for those sites that must use this functionality but desire the other security fixes.
For the stable distribution (woody) this problem has been fixed in version 1.2.4-5woody4.
The old stable distribution (potato) does not contain krb5 packages.
For the unstable distribution (sid) this problem will be fixed soon.
We recommend that you upgrade your krb5 package.
MD5 checksums of the listed files are available in the original advisory.