Red Hat Bugzilla – Bug 157104
CAN-2005-1174 krb5 buffer overflow, heap corruption in KDC (CAN-2005-1175)
Last modified: 2007-12-18 10:21:31 EST
+++ This bug was initially created as a clone of Bug #157103 +++
The MIT krb5 Key Distribution Center (KDC) implementation can corrupt
the heap by attempting to free memory at a random address when it
receives a certain unlikely (but valid) request via a TCP connection.
This attempt to free unallocated memory can result in a KDC crash and
consequent denial of service. [CAN-2005-1174]
Additionally, the same request, when received by the KDC via either
TCP or UDP, can trigger a bug in the krb5 library which results in a
single-byte overflow of a heap buffer. Additionally, application
servers are vulnerable to a highly improbable attack, provided that
the attacker controls a realm sharing a cross-realm key with the
target realm. [CAN-2005-1175]
An unauthenticated attacker may be able to use these vulnerabilities
to execute arbitrary code on the KDC host, potentially compromising an
entire Kerberos realm. No exploit code is known to exist at this
time. Exploitation of these vulnerabilities is believed to be
FC4 will be out before the embargo on this issue is lifted, we'll have to keep
that in mind.
According to MIT, in order to exploit CAN-2005-1175 the attacker must control a
realm sharing a cross-realm key with the target realm. I'm lowering the
severity to "moderate" for that particular issue.
public at http://web.mit.edu/kerberos/www/advisories/ removing embargo
This report targets the FC3 or FC4 products, which have now been EOL'd.
Could you please check that it still applies to a current Fedora release, and
either update the target product or close it ?
Issue was fixed in upstream version 1.4.2. All current Fedora versions ship
version 1.6+. Closing.