Bug 1443487 (CVE-2017-6441)

Summary:	CVE-2017-6441 php: Null pointer dereference via crafted "declare(ticks="
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abhgupta, fedora, hhorak, jorton, kseifried, rcollet, tiwillia, webstack-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-04-27 05:25:39 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:	1443534
Bug Blocks:	1443491

Description Adam Mariš 2017-04-19 10:56:52 UTC

The _zval_get_long_func_ex in Zend/zend_operators.c in PHP 7.1.2 allows attackers to cause a denial of service (NULL pointer dereference and application crash) via crafted use of "declare(ticks=" in a PHP script.

Upstream issue:

https://github.com/php/php-src/pull/2396

Comment 1 Adam Mariš 2017-04-19 12:41:17 UTC

Created php tracking bugs for this issue:

Affects: fedora-all [bug 1443534]

Comment 2 Doran Moppert 2017-04-27 05:25:39 UTC

Upstream bug:

https://bugs.php.net/bug.php?id=74146

I agree with the vendor's assessment:  this is not a security issue.  It is a crash triggered by executing (essentially) arbitrary PHP code.  Taking an untrusted value from the user and putting it in `declare(ticks=%s)` is not something done in practice, as it is likely to expose your system to denial of service even without this bug.