OWASP ModSecurity 2.9.8/2.9.10 Empty XML Tag memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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5.8$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in OWASP ModSecurity 2.9.8/2.9.10. This vulnerability affects unknown code of the component Empty XML Tag Handler. Such manipulation leads to memory corruption. This vulnerability is documented as CVE-2025-52891. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in OWASP ModSecurity 2.9.8/2.9.10 and classified as critical. Affected by this issue is an unknown function of the component Empty XML Tag Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is availability. CVE summarizes:

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one XML tag is empty (eg ), then a segmentation fault occurs. This issue has been patched in version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2025-52891 since 06/20/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 253505 (TencentOS Server 4: mod_security (TSSA-2025:0553)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.9.11 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (253505) and EUVD (EUVD-2025-19726). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 253505
Nessus Name: TencentOS Server 4: mod_security (TSSA-2025:0553)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: ModSecurity 2.9.11

Timelineinfo

06/20/2025 CVE reserved
07/02/2025 +12 days Advisory disclosed
07/02/2025 +0 days VulDB entry created
08/21/2025 +50 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2025-52891 (🔒)
GCVE (CVE): GCVE-0-2025-52891
GCVE (VulDB): GCVE-100-314636
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20130913

Entryinfo

Created: 07/02/2025 17:30
Updated: 08/21/2025 19:49
Changes: 07/02/2025 17:30 (64), 07/02/2025 18:26 (1), 08/21/2025 19:49 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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