CVE-2025-2905: WSO2 API Manager XXE Vulnerability

CVE-2025-2905 Overview

CVE-2025-2905 is a critical XML External Entity (XXE) injection vulnerability affecting multiple WSO2 Products, including WSO2 API Manager. The vulnerability stems from improper configuration of the XML parser, which allows user-supplied XML to be parsed without applying sufficient restrictions. This enables malicious XXE resolution that can be exploited by remote, unauthenticated attackers.

A successful exploitation of this vulnerability could allow an attacker to read sensitive files from the server's filesystem or perform denial-of-service (DoS) attacks, rendering the affected service unavailable.

Critical Impact

Remote unauthenticated attackers can exploit this XXE vulnerability to exfiltrate sensitive server files or cause service disruption through denial-of-service attacks.

Affected Products

• WSO2 API Manager (all vulnerable versions)
• Additional WSO2 Products as identified in the security advisory

Discovery Timeline

• 2025-05-05 - CVE-2025-2905 published to NVD
• 2025-10-16 - Last updated in NVD database

Technical Details for CVE-2025-2905

Vulnerability Analysis

This vulnerability is classified as CWE-611 (Improper Restriction of XML External Entity Reference). The root issue lies in how WSO2 products handle XML parsing operations. When an XML parser is configured to process external entity references without proper restrictions, it becomes susceptible to XXE attacks.

In the context of WSO2 API Manager, the XML parser accepts and processes user-controlled XML input. Without appropriate security controls such as disabling DTD processing or external entity resolution, the parser will attempt to resolve any external entities defined within the malicious XML payload.

The attack can be executed remotely over the network without requiring any authentication or user interaction, making it particularly dangerous for internet-facing deployments of WSO2 products.

Root Cause

The vulnerability originates from improper XML parser configuration within the WSO2 product suite. XML parsers by default may allow the processing of Document Type Definitions (DTDs) and external entity references. When developers fail to explicitly disable these features, the application becomes vulnerable to XXE attacks.

The secure configuration would require explicitly disabling features such as:

• External general entities
• External parameter entities
• DTD processing
• XInclude processing

Attack Vector

An attacker can exploit this vulnerability by submitting a crafted XML document containing malicious external entity declarations to any endpoint that processes XML input. The attack is network-based and requires no authentication, allowing any remote attacker to attempt exploitation.

The XXE payload can reference local files on the server using file system protocols, enabling the attacker to read sensitive configuration files, credentials, or other critical data. Additionally, by referencing extremely large or recursive entities, an attacker can trigger resource exhaustion leading to denial of service.

For detailed technical information about the exploitation mechanism, refer to the WSO2 Security Advisory #2025-3993.

Detection Methods for CVE-2025-2905

Indicators of Compromise

• Unusual XML processing errors in application logs containing references to external entities or DTD processing
• Server access attempts to internal file paths such as /etc/passwd, /etc/shadow, or Windows system files
• Outbound network connections from the WSO2 server to unexpected external hosts during XML processing
• Application logs showing file access attempts to sensitive configuration files outside normal operation

Detection Strategies

• Deploy Web Application Firewalls (WAF) with rules to detect XXE payloads in incoming requests
• Implement deep packet inspection to identify XML documents containing <!DOCTYPE> declarations with external entity references
• Monitor for requests containing suspicious XML constructs such as <!ENTITY declarations or SYSTEM keywords
• Enable verbose XML parser logging to capture attempts to resolve external entities

Monitoring Recommendations

• Monitor server logs for file access patterns indicative of XXE exploitation attempts
• Set up alerts for unusual outbound connections from the API Manager server
• Track resource utilization for potential DoS conditions caused by entity expansion attacks
• Review access logs for repeated XML parsing errors from single source IPs

How to Mitigate CVE-2025-2905

Immediate Actions Required

• Review and apply the official security patch from WSO2 as documented in the security advisory
• Audit all WSO2 deployments to identify vulnerable instances of API Manager
• Implement network-level controls to restrict access to the WSO2 management interfaces
• Enable enhanced logging to detect any exploitation attempts

Patch Information

WSO2 has released security patches to address this vulnerability. Organizations should consult the WSO2 Security Advisory #2025-3993 for specific patching instructions and affected version details.

Apply the vendor-provided patches as soon as possible following your organization's change management procedures. Ensure all WSO2 product instances are updated to versions that include the security fix.

Workarounds

• Configure XML parsers to disable DTD processing and external entity resolution if patches cannot be immediately applied
• Deploy WAF rules to block incoming requests containing XXE payloads
• Implement network segmentation to limit the exposure of vulnerable WSO2 instances
• Restrict access to XML-processing endpoints to trusted sources only

# Example XML parser hardening configuration
# Disable external entities in Java XML parsers
# Add these system properties to your WSO2 startup configuration:
-Djavax.xml.accessExternalDTD=""
-Djavax.xml.accessExternalSchema=""
-Djavax.xml.accessExternalStylesheet=""