krb5 - buffer overflow, double-free memory

Daniel Wachdorf reported two problems in the MIT krb5 distribution used
for network authentication. First, the KDC program from the krb5-kdc
package can corrupt the heap by trying to free memory which has already
been freed on receipt of a certain TCP connection. This vulnerability
can cause the KDC to crash, leading to a denial of service.
[CAN-2005-1174] Second, under certain rare circumstances this type of
request can lead to a buffer overflow and remote code execution.
[CAN-2005-1175]

Additionally, Magnus Hagander reported another problem in which the
krb5_recvauth function can in certain circumstances free previously
freed memory, potentially leading to the execution of remote code.
[CAN-2005-1689]

All of these vulnerabilities are believed difficult to exploit, and no
exploits have yet been discovered.

For the old stable distribution (woody), these problems have been fixed
in version 1.2.4-5woody10. Note that woody’s KDC does not have TCP
support and is not vulnerable to CAN-2005-1174.

For the stable distribution (sarge), these problems have been fixed in
version 1.3.6-2sarge2.

For the unstable distribution (sid), these problems have been fixed in
version 1.3.6-4.

We recommend that you upgrade your krb5 package.