krb5 (SL7)

Synopsis: Moderate: krb5 security, bug fix and enhancement update
Advisory ID: SLSA-2015:0439-1
Issue Date: 2015-03-05
CVE Numbers: CVE-2014-4341

A buffer overflow was found in the KADM5 administration server (kadmind)
when it was used with an LDAP back end for the KDC database. A remote,
authenticated attacker could potentially use this flaw to execute
arbitrary code on the system running kadmind. (CVE-2014-4345)

A use-after-free flaw was found in the way the MIT Kerberos libgssapi_krb5
library processed valid context deletion tokens. An attacker able to make
an application using the GSS-API library (libgssapi) call the
gss_process_context_token() function could use this flaw to crash that
application. (CVE-2014-5352)

If kadmind were used with an LDAP back end for the KDC database, a remote,
authenticated attacker with the permissions to set the password policy
could crash kadmind by attempting to use a named ticket policy object as a
password policy for a principal. (CVE-2014-5353)

A double-free flaw was found in the way MIT Kerberos handled invalid
External Data Representation (XDR) data. An authenticated user could use
this flaw to crash the MIT Kerberos administration server (kadmind), or
other applications using Kerberos libraries, using specially crafted XDR
packets. (CVE-2014-9421)

It was found that the MIT Kerberos administration server (kadmind)
incorrectly accepted certain authentication requests for two-component
server principal names. A remote attacker able to acquire a key with a
particularly named principal (such as “kad/x”) could use this flaw to
impersonate any user to kadmind, and perform administrative actions as
that user. (CVE-2014-9422)

An information disclosure flaw was found in the way MIT Kerberos
RPCSEC_GSS implementation (libgssrpc) handled certain requests. An
attacker could send a specially crafted request to an application using
libgssrpc to disclose a limited portion of uninitialized memory used by
that application. (CVE-2014-9423)

Two buffer over-read flaws were found in the way MIT Kerberos handled
certain requests. A remote, unauthenticated attacker able to inject
packets into a client or server application’s GSSAPI session could use
either of these flaws to crash the application. (CVE-2014-4341,

A double-free flaw was found in the MIT Kerberos SPNEGO initiators. An
attacker able to spoof packets to appear as though they are from an GSSAPI
acceptor could use this flaw to crash a client application that uses MIT
Kerberos. (CVE-2014-4343)

The krb5 packages have been upgraded to upstream version 1.12, which
provides a number of bug fixes and enhancements, including:

* Added plug-in interfaces for principal-to-username mapping and verifying
authorization to user accounts.

* When communicating with a KDC over a connected TCP or HTTPS socket, the
client gives the KDC more time to reply before it transmits the request to
another server.

This update also fixes multiple bugs, for example:

* The Kerberos client library did not recognize certain exit statuses that
the resolver libraries could return when looking up the addresses of
servers configured in the /etc/krb5.conf file or locating Kerberos servers
using DNS service location. The library could treat non-fatal return codes
as fatal errors. Now, the library interprets the specific return codes

In addition, this update adds various enhancements. Among others:

* Added support for contacting KDCs and kpasswd servers through HTTPS
proxies implementing the Kerberos KDC Proxy (KKDCP) protocol.


– Scientific Linux Development Team