PHP 7.x Unserialization use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.4$0-$5k0.00

A vulnerability, which was classified as critical, has been found in PHP 7.x (Programming Language Software). This issue affects some unknown functionality of the component Unserialization. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In all versions of PHP 7, during the unserialization process, resizing the 'properties' hash table of a serialized object may lead to use-after-free. A remote attacker may exploit this bug to gain arbitrary code execution.

The bug was discovered 12/27/2016. The weakness was published 01/12/2017 with CheckPoint (Website). It is possible to read the advisory at blog.checkpoint.com. The identification of this vulnerability is CVE-2016-7479 since 09/09/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 15 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 96800 (PHP 7.0.x < 7.0.15 Multiple Vulnerabilities), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CGI abuses and running in the context r. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196693 (Ubuntu Security Notification for Php5 Vulnerabilities (USN-3196-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 1 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (96800). Similar entries are available at 95027, 95169, 95170 and 95171.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Dayunlockunlockunlockunlock
Todayunlockunlockunlockunlock

Nessus ID: 96800
Nessus Name: PHP 7.0.x < 7.0.15 Multiple Vulnerabilities
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 850584
OpenVAS Name: SuSE Update for php7 openSUSE-SU-2017:0588-1 (php7)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

09/09/2016 🔍
12/27/2016 +109 days 🔍
12/29/2016 +2 days 🔍
01/11/2017 +13 days 🔍
01/12/2017 +1 days 🔍
01/12/2017 +0 days 🔍
01/19/2017 +7 days 🔍
01/26/2017 +7 days 🔍
10/28/2022 +2101 days 🔍

Sourcesinfo

Product: php.org

Advisory: RHSA-2018:1296
Organization: CheckPoint
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-7479 (🔍)
SecurityTracker: 1037659
SecurityFocus: 95151 - PHP CVE-2016-7479 Denial of Service Vulnerability
OSVDB: - CVE-2016-7479 - PHP - Use-After-Free Issue

See also: 🔍

Entryinfo

Created: 01/12/2017 10:31 AM
Updated: 10/28/2022 12:18 PM
Changes: 01/12/2017 10:31 AM (74), 07/20/2020 11:09 AM (9), 10/28/2022 12:18 PM (4)
Complete: 🔍

Discussion

No comments yet. Languages: en.

Please log in to comment.

Do you need the next level of professionalism?

Upgrade your account now!