Family: Debian Local Security Checks --> Category: infos
[DSA269] DSA-269-1 heimdal Vulnerability Scan
Vulnerability Scan Summary
Detailed Explanation for this Vulnerability Test
A cryptographic weakness in version 4 of the Kerberos protocol allows
a possible hacker to use a chosen-plaintext attack to impersonate any
principal in a realm. Additional cryptographic weaknesses in the krb4
implementation permit the use of cut-and-paste attacks to fabricate
krb4 tickets for unauthorized client principals if triple-DES keys are
used to key krb4 services. These attacks can subvert a site's entire
Kerberos authentication infrastructure.
This version of the heimdal 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 (--kerberos4-cross-realm) is provided to the kdc
command to re-enable version 4 cross-realm authentication for those
sites that must use this functionality but desire the other security
For the stable distribution (woody) this problem has been
fixed in version 0.4e-7.woody.8.
The old stable distribution (potato) is not affected by this problem,
since it isn't compiled against kerberos 4.
For the unstable distribution (sid) this problem has been
fixed in version 0.5.2-1.
We recommend that you upgrade your heimdal packages immediately.
Solution : http://www.debian.org/security/2003/dsa-269
Threat Level: High
Click HERE for more information and discussions on this network vulnerability scan.