Bug 1121877 (CVE-2014-4344)

Summary:	CVE-2014-4344 krb5: NULL pointer dereference flaw in SPNEGO acceptor for continuation tokens
Product:	[Other] Security Response	Reporter:	Murray McAllister <mmcallis>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	angelo.alvarez, carnil, dpal, dsirrine, jplans, jrusnack, mdshaikh, nalin, nathaniel, pkis, rmainz, sashaikh, sisharma
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	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.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-03-06 10:11:21 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1121509, 1121510, 1121511, 1121879
Bug Blocks:	1101912, 1121513, 1121882

Description Murray McAllister 2014-07-22 06:25:03 UTC

A NULL pointer dereference flaw was found in the MIT Kerberos SPNEGO acceptor for continuation tokens. An unauthenticated attacker could use this flaw to crash the server acceptor.

It is reported that this issue affects version 1.5 and later.

Upstream commit and further details:

https://github.com/krb5/krb5/commit/524688ce87a15fc75f87efc8c039ba4c7d5c197b

Comment 1 Murray McAllister 2014-07-22 06:27:43 UTC

Created krb5 tracking bugs for this issue:

Affects: fedora-all [bug 1121879]

Comment 3 Siddharth Sharma 2014-07-27 12:36:29 UTC

Successful exploitation of this flaw requires that attacker must provide at least one valid context token in the security context negotiation before sending the empty token.This can be done using unauthenticated AS-REQ as the first token and then sending the empty token which would case a crash of the server, at this point attacker is not authenticated.

Comment 4 Siddharth Sharma 2014-07-28 06:56:42 UTC

Statement:

(none)

Comment 8 Fedora Update System 2014-08-07 15:27:15 UTC

krb5-1.11.3-24.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2014-08-07 15:32:47 UTC

krb5-1.11.5-10.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 10 Angelo Alvarez 2014-09-06 00:26:44 UTC

Are the krb5-libs packages for RHEL5 and RHEL6 affected by this vulnerability?

Comment 12 Martin Prpič 2014-09-09 09:47:26 UTC

IssueDescription:

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.

Comment 13 errata-xmlrpc 2014-09-16 05:29:27 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5

Via RHSA-2014:1245 https://rhn.redhat.com/errata/RHSA-2014-1245.html

Comment 14 errata-xmlrpc 2014-10-14 08:11:13 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2014:1389 https://rhn.redhat.com/errata/RHSA-2014-1389.html

Comment 16 errata-xmlrpc 2015-03-05 10:01:17 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2015:0439 https://rhn.redhat.com/errata/RHSA-2015-0439.html