Deserialization of Untrusted Data in PHP

1) Deserialization of Untrusted Data

EUVDB-ID: #VU16138

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2016-7124

CWE-ID: CWE-502 - Deserialization of Untrusted Data

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing certain objects in "ext/standard/var_unserializer.c" PHP extension. A remote attacker can pass specially crafted data to the application and execute arbitrary code on the target system via "__destruct" or "magic" method calls.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

PHP: 5.6.0 - 7.0.9

CPE2.3

• cpe:2.3:a:php_group:php:5.6.0:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.1:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.2:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.3:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.4:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.5:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.6:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.7:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.8:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.9:*:*:*:*:*:*:*

External links

https://openwall.com/lists/oss-security/2016/09/02/9
https://www.php.net/ChangeLog-5.php
https://www.php.net/ChangeLog-7.php
https://www.securityfocus.com/bid/92756
https://www.securitytracker.com/id/1036680
https://bugs.php.net/bug.php?id=72663
https://github.com/php/php-src/commit/20ce2fe8e3c211a42fee05a461a5881be9a8790e?w=1
https://security.gentoo.org/glsa/201611-22
https://www.tenable.com/security/tns-2016-19

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.