Synopsis: Moderate: krb5 security and bug fix update
Advisory ID: SLSA-2014:1245-1
Issue Date: 2014-09-16
CVE Numbers: CVE-2013-1418
It was found that if a KDC served multiple realms, certain requests could
cause the setup_server_realm() function to dereference a NULL pointer. A
remote, unauthenticated attacker could use this flaw to crash the KDC
using a specially crafted request. (CVE-2013-1418, CVE-2013-6800)
A NULL pointer dereference flaw was found in the MIT Kerberos SPNEGO
acceptor for continuation tokens. A remote, unauthenticated attacker could
use this flaw to crash a GSSAPI-enabled server application.
A buffer over-read flaw was found in the way MIT Kerberos handled certain
requests. A man-in-the-middle attacker with a valid Kerberos ticket who is
able to inject packets into a client or server application’s GSSAPI
session could use this flaw to crash the application. (CVE-2014-4341)
This update also fixes the following bugs:
* Prior to this update, the libkrb5 library occasionally attempted to free
already freed memory when encrypting credentials. As a consequence, the
calling process terminated unexpectedly with a segmentation fault. With
this update, libkrb5 frees memory correctly, which allows the credentials
to be encrypted appropriately and thus prevents the mentioned crash.
* Previously, when the krb5 client library was waiting for a response from
a server, the timeout variable in certain cases became a negative number.
Consequently, the client could enter a loop while checking for responses.
With this update, the client logic has been modified and the described
error no longer occurs.
After installing the updated packages, the krb5kdc daemon will be
– Scientific Linux Development Team