PHP up to 7.1.32 FPM fpm_main.c env_path_info Underflow out-of-bounds write

EntryHistoryDiffjsonxmlCTI

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-$5k	0.00

A vulnerability was found in PHP up to 7.1.32 (Programming Language Software). It has been classified as critical. This affects the function env_path_info of the file fpm_main.c of the component FPM. The manipulation with an unknown input leads to a out-of-bounds write vulnerability (Underflow). CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus opening the possibility of remote code execution.

The weakness was released 10/24/2019 as Version 7.1.33 as confirmed changelog (Website). It is possible to read the advisory at php.net. This vulnerability is uniquely identified as CVE-2019-11043. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details and a public exploit are known.

After 2 days, there has been an exploit disclosed. The exploit is shared for download at bugs.php.net. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $5k-$25k. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 03/25/2022 with a due date of 04/15/2022:

Apply updates per vendor instructions.

Upgrading to version 7.1.33 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

Further details are available at bugs.php.net.

Productinfo

Type

Programming Language Software

Name

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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CVSSv3info

VulDB Meta Base Score: 8.6
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 6.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CNA Base Score: 8.7
CNA Vector (PHP Group): 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
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Exploitinginfo

Name: Underflow
Class: Out-of-bounds write / Underflow
CWE: CWE-787 / CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

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EPSS Percentile: 🔍

KEV Added: 🔍
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KEV Remediation: 🔍
KEV Ransomware: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: PHP 7.1.33

Timelineinfo

04/09/2019 🔍
10/24/2019 +198 days 🔍
10/24/2019 +0 days 🔍
10/26/2019 +2 days 🔍
10/26/2019 +0 days 🔍
01/29/2024 +1556 days 🔍

Sourcesinfo

Product: php.org

Advisory: Version 7.1.33
Status: Confirmed

CVE: CVE-2019-11043 (🔍)
scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍

Entryinfo

Created: 10/26/2019 15:59
Updated: 01/29/2024 09:46
Changes: 10/26/2019 15:59 (50), 10/26/2019 16:04 (17), 01/29/2024 09:41 (4), 01/29/2024 09:46 (12)
Complete: 🔍
Submitter: misc

Submitinfo

Accepted

Submit #110: PHP-FPM env_path_info underflow in fpm_main.c can lead to RCE (by misc)