Double free vulnerability in dotgsreq.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7.x and 1.8.x before 1.8.2 allows remote authenticated users to cause a denial of service (daemon crash) or possibly execute arbitrary code via a request associated with (1) renewal or (2) validation.

MIT Kerberos 5 version 1.10.2 was released [1] and noted as fixing:

Fix a kadmind denial of service issue (null pointer dereference), which could only be triggered by an administrator with the "create" privilege. [CVE-2012-1013]

No information is currently available on which versions are affected by this flaw.

[1] http://mailman.mit.edu/pipermail/kerberos-announce/2012q2/000136.html

The kdchandleprotectednegotiation function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8.x, 1.9.x before 1.9.5, and 1.10.x before 1.10.3 attempts to calculate a checksum before verifying that the key type is appropriate for a checksum, which allows remote attackers to execute arbitrary code or cause a denial of service (uninitialized pointer free, heap memory corruption, and daemon crash) via a crafted AS-REQ request.

MIT Kerberos 5 (aka krb5) 1.7.x through 1.12.x before 1.12.2 allows remote attackers to cause a denial of service (buffer over-read or NULL pointer dereference, and application crash) by injecting invalid tokens into a GSSAPI application session.

Off-by-one error in the krb5encodekrbsecretkey function in plugins/kdb/ldap/libkdbldap/ldapprincipal2.c in the LDAP KDB module in kadmind in MIT Kerberos 5 (aka krb5) 1.6.x through 1.11.x before 1.11.6 and 1.12.x before 1.12.2 allows remote authenticated users to cause a denial of service (buffer overflow) or possibly execute arbitrary code via a series of "cpw -keepold" commands.

In MIT Kerberos 5 (aka krb5) 1.7 and later, an authenticated attacker can cause a KDC assertion failure by sending invalid S4U2Self or S4U2Proxy requests.