Bug 1285408 (CVE-2015-2327)

Summary:	CVE-2015-2327 pcre: infinite recursion compiling pattern with zero-repeated groups that include recursive back reference (8.36/19)
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	carnil, jorton, lkundrak, mmaslano, ppisar, rcollet, rmeggins, sardella, slawomir, webstack-team
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	pcre 8.36	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-04-27 07:39:16 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:	1119272, 1119356, 1285409
Bug Blocks:	1285420

Description Adam Mariš 2015-11-25 14:33:40 UTC

A stack-based buffer overflow vulnerability was found in compile_regex(), triggered via crafted regular expression.

Upstream bug (contains reproducer):

https://bugs.exim.org/show_bug.cgi?id=1503

Upstream patch:

http://vcs.pcre.org/pcre?view=revision&revision=1495

CVE request:

http://www.openwall.com/lists/oss-security/2015/05/31/5

Comment 1 Adam Mariš 2015-11-25 14:34:14 UTC

Created pcre tracking bugs for this issue:

Affects: fedora-all [bug 1285409]

Comment 2 Petr Pisar 2015-11-25 16:25:43 UTC

Upstream fixed it in 8.36 version. A reproducer is crash when compiling /(((a\2)|(a*)\g<-1>))*a?/BZ expression in pcretest tool.

Comment 3 Petr Pisar 2015-11-25 16:34:21 UTC

This was fixed with pcre-8.35-4.fc21 in Fedora on 2014-07-14. No supported Fedora is affected now.

Comment 4 Tomas Hoger 2016-02-18 11:43:14 UTC

This is not a stack based buffer overflow, but stack overflow, caused by infinite recursion.  The impact of this issue is limited to crash.

The problem was introduced upstream between version 8.00 and 8.01.

Comment 6 Petr Pisar 2016-04-27 07:04:43 UTC

This has already been fixed with pcre-8.32-15.el7 as bug #1119356. RHEL-7.2 is not affected.

Comment 7 Tomas Hoger 2016-04-27 07:39:16 UTC

Ok, thank you for the correction.  So the fix is included in pcre packages released via RHBA-2015:2142, which is part of Red Hat Enterprise Linux 7.2 update:

https://rhn.redhat.com/errata/RHBA-2015-2142.html

Comment 9 errata-xmlrpc 2016-11-15 11:47:29 UTC

This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7
  Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS

Via RHSA-2016:2750 https://rhn.redhat.com/errata/RHSA-2016-2750.html