Ga�l Delalleau discovered a buffer overflow in the env_opt_add() function of the Kerberos 4 and 5 telnet clients. By sending specially crafted replies, a malicious telnet server could exploit this to execute arbitrary code with the privileges of the user running the telnet client. (CVE-2005-0468)
Ga�l Delalleau discovered a buffer overflow in the handling of the LINEMODE suboptions in the telnet clients of Kerberos 4 and 5. By sending a specially constructed reply containing a large number of SLC (Set Local Character) commands, a remote attacker (i. e. a malicious telnet server) could execute arbitrary commands with the privileges of the user running the telnet client. (CVE-2005-0469)
Daniel Wachdorf discovered two remote vulnerabilities in the Key Distribution Center of Kerberos 5 (krb5-kdc). By sending certain TCP connection requests, a remote attacker could trigger a double-freeing of memory, which led to memory corruption and a crash of the KDC server. (CVE-2005-1174). Under rare circumstances the same type of TCP connection requests could also trigger a buffer overflow that could be exploited to run arbitrary code with the privileges of the KDC server. (CVE-2005-1175)
Magnus Hagander discovered that the krb5_recvauth() function attempted to free previously freed memory in some situations. A remote attacker could possibly exploit this to run arbitrary code with the privileges of the program that called this function. Most imporantly, this affects the following daemons: kpropd (from the krb5-kdc package), klogind, and kshd (both from the krb5-rsh-server package). (CVE-2005-1689)
Please note that these packages are not officially supported by Ubuntu (they are in the ‘universe’ component of the archive).