Arch Linux: 201502-12 High: KRB5 Remote Code Execution and More

The package krb5 before version 1.13.1-1 is vulnerable to multiple issues including authenticated remote code execution, authenticated remote denial of service, authenticated remote privilege escalation and remote information leak.

Arch Linux Security Advisory ASA-201502-12
=========================================
Severity: High
Date    : 2015-02-17
CVE-ID  : CVE-2014-5352 CVE-2014-5353 CVE-2014-5354 CVE-2014-9421
CVE-2014-9422 CVE-2014-9423
Package : krb5
Type    : multiple issues
Remote  : Yes
Link    : https://wiki.archlinux.org/title/CVE

Summary
======
The package krb5 before version 1.13.1-1 is vulnerable to multiple
issues including authenticated remote code execution, authenticated
remote denial of service, authenticated remote privilege escalation and
remote information leak.

Resolution
=========
Upgrade to 1.13.1-1.

# pacman -Syu "krb5>=1.13.1-1"

The problem has been fixed upstream in version 1.13.1.

Workaround
=========
None.

Description
==========
- CVE-2014-5352 (authenticated remote code execution):

In the MIT krb5 libgssapi_krb5 library, after
gss_process_context_token() is used to process a valid context deletion
token, the caller is left with a security context handle containing a
dangling pointer.  Further uses of this handle will result in
use-after-free and double-free memory access violations. libgssrpc
server applications such as kadmind are vulnerable as they can be
instructed to call gss_process_context_token().

- CVE-2014-5353 (authenticated remote denial of service):

In MIT krb5, when kadmind is configured to use LDAP for the KDC
database, an authenticated remote attacker can cause a NULL dereference
by attempting to use a named ticket policy object as a password policy
for a principal.  The attacker needs to be authenticated as a user who
has the elevated privilege for setting password policy by adding or
modifying principals.

- CVE-2014-5354 (authenticated remote denial of service):

In MIT krb5, when kadmind is configured to use LDAP for the KDC
database, an authenticated remote attacker can cause a NULL dereference
by inserting into the database a principal entry which contains no
long-term keys.

- CVE-2014-9421 (authenticated remote code execution):

If the MIT krb5 kadmind daemon receives invalid XDR data from an
authenticated user, it may perform use-after-free and double-free memory
access violations while cleaning up the partial deserialization results.
 Other libgssrpc server applications may also be vulnerable if they
contain insufficiently defensive XDR functions.

- CVE-2014-9422 (privilege escalation):

The MIT krb5 kadmind daemon incorrectly accepts authentications to
two-component server principals whose first component is a left
substring of "kadmin" or whose realm is a left prefix of the default realm.

- CVE-2014-9423 (unauthenticated remote information leak):

libgssrpc applications including kadmind output four or eight bytes of
uninitialized memory to the network as part of an unused "handle" field
in replies to clients.

Impact
=====
A remote, unauthenticated attacker can retrieve sensitive information
from the memory of the affected system.

A remote authenticated attacker can crash the affected process, escalate
to administrative privileges and execute arbitrary code.

References
=========
http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2015-001.txt
https://access.redhat.com/security/cve/CVE-2014-5352
https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-5353
https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-5354
https://access.redhat.com/security/cve/CVE-2014-9421
https://access.redhat.com/security/cve/CVE-2014-9422
https://access.redhat.com/security/cve/CVE-2014-9423
https://www.openwall.com/lists/oss-security/2014/12/16/1