Bug 1361050 (CVE-2016-3120)

Summary:	CVE-2016-3120 krb5: S4U2Self KDC crash when anon is restricted
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abokovoy, bbaranow, bmaxwell, cdewolf, csutherl, dandread, darran.lofthouse, dkholia, dosoudil, dpal, fnasser, gzaronik, jason.greene, jawilson, jboss-set, jclere, jdoyle, jplans, jshepherd, j, lgao, mbabacek, myarboro, nalin, npmccallum, pgier, pkis, psakar, pslavice, rharwood, rnetuka, rsvoboda, sardella, slawomir, twalsh, vtunka, weli
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A NULL pointer dereference flaw was found in MIT Kerberos krb5kdc service. An authenticated attacker could use this flaw to cause krb5kdc to dereference a null pointer and crash by making an S4U2Self request, if the restrict_anonymous_to_tgt option was set to true.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-11-06 04:20:17 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:	1361051, 1361504
Bug Blocks:	1323912, 1361052

Description Adam Mariš 2016-07-28 09:19:46 UTC

It was found that in MIT krb5 1.9 and later, an authenticated attacker can cause krb5kdc to dereference a null pointer if the restrict_anonymous_to_tgt option is set to true, by making an S4U2Self request.

Upstream patch:

https://github.com/krb5/krb5/commit/93b4a6306a0026cf1cc31ac4bd8a49ba5d034ba7

Comment 1 Adam Mariš 2016-07-28 09:20:20 UTC

Created krb5 tracking bugs for this issue:

Affects: fedora-all [bug 1361051]

Comment 3 Fedora Update System 2016-08-01 16:23:05 UTC

krb5-1.14.1-8.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

Comment 4 Fedora Update System 2016-08-31 12:21:45 UTC

krb5-1.14.3-4.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2016-09-01 18:50:23 UTC

krb5-1.14.3-8.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 8 errata-xmlrpc 2016-11-03 20:25:33 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2591 https://rhn.redhat.com/errata/RHSA-2016-2591.html