Debian DSA-757-1 : krb5 - buffer overflow, double-free memory
High Nessus Plugin ID 19219
SynopsisThe remote Debian host is missing a security-related update.
DescriptionDaniel 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.
SolutionUpgrade the krb5 package.
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.