Bug 1351168 (CVE-2016-5768)

Summary:	CVE-2016-5768 php: Double free in _php_mb_regex_ereg_replace_exec
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abhgupta, dmcphers, fedora, hhorak, jialiu, jokerman, jorton, lmeyer, mmccomas, rcollet, tiwillia, webstack-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	php 5.5.37, php 5.6.23	Doc Type:	If docs needed, set a value
Doc Text:	A double free flaw was found in the mb_ereg_replace_callback() function of php which is used to perform regex search. This flaw could possibly cause a PHP application to crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:56:04 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:	1351180, 1356812
Bug Blocks:	1323912, 1351183

Description Andrej Nemec 2016-06-29 11:49:33 UTC

The _php_mb_regex_ereg_replace_exec when called by mb_ereg_replace_callback frees the description twice in case when callback execution failed (i.e. threw an exception).

Upstream bug:

https://bugs.php.net/bug.php?id=72402

Upstream patch:

http://git.php.net/?p=php-src.git;a=commitdiff;h=5b597a2e5b28e2d5a52fc1be13f425f08f47cb62

CVE assignment:

http://seclists.org/oss-sec/2016/q2/589

Comment 1 Andrej Nemec 2016-06-29 12:05:05 UTC

Created php tracking bugs for this issue:

Affects: fedora-all [bug 1351180]

Comment 2 Fedora Update System 2016-07-02 15:27:23 UTC

php-5.6.23-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

Comment 3 Fedora Update System 2016-07-02 19:22:11 UTC

php-5.6.23-1.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 4 Fedora Update System 2016-07-02 19:27:30 UTC

php-5.6.23-1.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 Huzaifa S. Sidhpurwala 2016-07-14 07:39:21 UTC

Analysis:

mb_ereg_replace_callback() is used to perform a regex search, the matched text is them replaced by output of the callback function. Script authors need to provide the callback function as the input to the function. In case the callback execution fails, (Most likely when the script author did not provide a proper callback), then a double-free takes places, causing php application crash.

Comment 7 errata-xmlrpc 2016-11-03 21:05:27 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2598 https://rhn.redhat.com/errata/RHSA-2016-2598.html

Comment 9 errata-xmlrpc 2016-11-15 11:41:37 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