Quantum Secular Labs / Blog / Advisories

CVE-2016-5772: PHP: Memory corruption

CVE-2016-5772 is rated critical with a CVSS v3.1 base score of 9.8 and affects PHP, along with 6 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

Double free vulnerability in the php_wddx_process_data function in wddx.c in the WDDX extension in PHP before 5.5.37, 5.6.x before 5.6.23, and 7.x before 7.0.8 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via crafted XML data that is mishandled in a wddx_deserialize call.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-415: Double Free

The product calls free() twice on the same memory address.

Affected products

PHP: before 5.5.37; from 5.6.0 before 5.6.23; from 7.0.0 before 7.0.8
Suse Linux Enterprise Debuginfo: 11 sp4
Opensuse Leap: 42.1
Opensuse: 13.2
Suse Linux Enterprise Server: 11 sp4
Suse Linux Enterprise Software Development Kit: 11 sp4
Debian Linux: 8.0