OSEC

Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email hr@neohapsis.com
[SA24356] PHP4 ZVAL Reference Counter Overflow Vulnerability

From: Secunia Security Advisories (sec-advsecunia.com)
Date: Mon Mar 05 2007 - 04:47:05 CST


----------------------------------------------------------------------

Want a new job?
http://secunia.com/secunia_vacancies/

Secunia is looking for new researchers with a reversing background
and experience in writing exploit code:
http://secunia.com/hardcore_disassembler_and_reverse_engineer/
http://secunia.com/Disassembling_og_Reversing/

----------------------------------------------------------------------

TITLE:
PHP4 ZVAL Reference Counter Overflow Vulnerability

SECUNIA ADVISORY ID:
SA24356

VERIFY ADVISORY:
http://secunia.com/advisories/24356/

CRITICAL:
Less critical

IMPACT:
Security Bypass

WHERE:
Local system

SOFTWARE:
PHP 4.4.x
http://secunia.com/product/5768/

DESCRIPTION:
Stefan Esser has discovered a vulnerability in PHP4, which can be
exploited by malicious, local users to bypass certain security
restrictions.

The vulnerability is caused due to an integer overflow in the
handling of ZVAL structures. This can be exploited to corrupt memory
and execute arbitrary code therefore bypassing security restrictions
like the "disable_functions" directive.

The vulnerability is confirmed in version 4.4.6. Other versions may
also be affected.

SOLUTION:
Grant only trusted users access to affected systems.

PROVIDED AND/OR DISCOVERED BY:
Stefan Esser

ORIGINAL ADVISORY:
http://www.php-security.org/MOPB/MOPB-01-2007.html

----------------------------------------------------------------------

About:
This Advisory was delivered by Secunia as a free service to help
everybody keeping their systems up to date against the latest
vulnerabilities.

Subscribe:
http://secunia.com/secunia_security_advisories/

Definitions: (Criticality, Where etc.)
http://secunia.com/about_secunia_advisories/

Please Note:
Secunia recommends that you verify all advisories you receive by
clicking the link.
Secunia NEVER sends attached files with advisories.
Secunia does not advise people to install third party patches, only
use those supplied by the vendor.

----------------------------------------------------------------------

Unsubscribe: Secunia Security Advisories

----------------------------------------------------------------------