Bug 157104

Summary: CAN-2005-1174 krb5 buffer overflow, heap corruption in KDC (CAN-2005-1175)
Product: [Fedora] Fedora Reporter: Josh Bressers <bressers>
Component: krb5Assignee: Nalin Dahyabhai <nalin>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: high Docs Contact:
Priority: medium    
Version: 4CC: security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,public=20050612,source=mit,reported=20050426
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-12-18 10:21:31 EST Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:

Description Josh Bressers 2005-05-06 17:06:48 EDT
+++ 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
difficult.
Comment 1 Josh Bressers 2005-05-06 17:07:34 EDT
FC4 will be out before the embargo on this issue is lifted, we'll have to keep
that in mind.
Comment 2 Josh Bressers 2005-07-07 09:01:32 EDT
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.
Comment 3 Mark J. Cox (Product Security) 2005-07-12 14:00:07 EDT
public at http://web.mit.edu/kerberos/www/advisories/ removing embargo
Comment 4 Christian Iseli 2007-01-22 06:05:26 EST
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 ?

Thanks.
Comment 5 Tomas Hoger 2007-12-18 10:21:31 EST
Issue was fixed in upstream version 1.4.2.  All current Fedora versions ship
version 1.6+.  Closing.