CVE-2025-12107: WSO2 Identity Server RCE Vulnerability

CVE-2025-12107 Overview

CVE-2025-12107 is a Server-Side Template Injection (SSTI) vulnerability affecting WSO2 Identity Server. The vulnerability exists due to the use of a vulnerable third-party Apache Velocity template engine, which allows a malicious actor with administrative privileges to inject and execute arbitrary template syntax within server-side templates.

Successful exploitation of this vulnerability could enable an attacker with admin access to inject and execute arbitrary template code on the server, potentially leading to remote code execution, data manipulation, or unauthorized access to sensitive information stored within the identity management platform.

Critical Impact

Authenticated administrators can achieve remote code execution through Velocity template injection, compromising the entire identity management infrastructure and potentially accessing sensitive user credentials and authentication data.

Affected Products

• WSO2 Identity Server 5.11.0
• WSO2 Identity Server (check vendor advisory for complete version list)

Discovery Timeline

• 2026-02-19 - CVE CVE-2025-12107 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2025-12107

Vulnerability Analysis

This vulnerability is classified under CWE-1336 (Improper Neutralization of Special Elements Used in a Template Engine). The flaw resides in WSO2 Identity Server's implementation of the Apache Velocity template engine, which fails to properly sanitize user-controlled input before processing it within server-side templates.

The vulnerability requires administrative privileges to exploit, which limits the attack surface but significantly amplifies the potential impact once access is obtained. An attacker with admin credentials can craft malicious Velocity Template Language (VTL) directives that escape the intended template context and execute arbitrary Java code on the underlying server.

The network-accessible nature of this vulnerability means that any authenticated administrator with network access to the WSO2 Identity Server management console can potentially exploit this flaw. Given that identity servers typically handle authentication tokens, user credentials, and access control policies, successful exploitation poses severe risks to organizational security.

Root Cause

The root cause of this vulnerability lies in the improper neutralization of special template elements before they are processed by the Velocity template engine. When user-supplied input containing Velocity directives (such as #set, #foreach, or direct method invocations via $object.method()) is incorporated into templates without adequate sanitization, attackers can manipulate the template processing logic.

The Velocity engine provides access to Java objects and methods through its context, which can be abused to instantiate arbitrary classes, invoke system commands, or access sensitive server resources.

Attack Vector

The attack vector for CVE-2025-12107 is network-based and requires authenticated administrative access to the WSO2 Identity Server. An attacker would need to:

1. Obtain valid administrative credentials through credential theft, social engineering, or exploitation of other vulnerabilities
2. Access administrative interfaces that accept template-related input
3. Inject malicious Velocity template syntax designed to achieve code execution
4. The template engine processes the malicious input, executing arbitrary commands with the privileges of the WSO2 Identity Server process

Common Velocity template injection payloads leverage reflection APIs to instantiate java.lang.Runtime objects for command execution or access file system resources. The specific injection points depend on which administrative features process user input through the Velocity engine.

Detection Methods for CVE-2025-12107

Indicators of Compromise

• Unusual administrative login patterns or access from unexpected IP addresses
• Anomalous template-related requests containing Velocity syntax characters (#, $, {})
• Server process spawning unexpected child processes or network connections
• Unexpected file system modifications in WSO2 Identity Server directories
• Log entries showing template parsing errors or unusual object method invocations

Detection Strategies

• Monitor administrative authentication logs for suspicious access patterns
• Implement web application firewall (WAF) rules to detect common SSTI payloads in HTTP requests
• Deploy endpoint detection solutions to identify anomalous process behavior from the WSO2 service
• Analyze HTTP request payloads for Velocity-specific syntax patterns in administrative endpoints
• Review audit logs for template modification activities by administrative users

Monitoring Recommendations

• Enable verbose logging for the WSO2 Identity Server administration console
• Configure SIEM alerts for template injection signature patterns in application logs
• Monitor system calls and process creation events from the Java process running WSO2
• Track outbound network connections from the identity server for potential reverse shell activity
• Implement file integrity monitoring for critical WSO2 configuration and template files

How to Mitigate CVE-2025-12107

Immediate Actions Required

• Review and restrict administrative access to the WSO2 Identity Server console
• Audit existing administrative accounts and remove unnecessary privileged access
• Implement network segmentation to limit administrative access to trusted networks only
• Enable multi-factor authentication for all administrative accounts
• Review audit logs for any suspicious administrative activity that may indicate prior exploitation

Patch Information

WSO2 has released a security advisory addressing this vulnerability. Organizations should consult the WSO2 Security Advisory WSO2-2025-4517 for specific patch versions and upgrade instructions.

Administrators should prioritize applying the official patch as it addresses the underlying template injection vulnerability in the Velocity engine integration.

Workarounds

• Restrict administrative console access to a dedicated management network segment
• Implement strict IP allowlisting for administrative interfaces
• Deploy a web application firewall with SSTI detection rules in front of the identity server
• Consider temporarily disabling features that utilize template processing if operationally feasible
• Enable enhanced logging and monitoring while awaiting patch deployment

# Example: Restrict administrative access via reverse proxy (nginx)
# Add to server block handling admin console
location /admin {
    allow 10.0.1.0/24;  # Management network only
    deny all;
    proxy_pass http://wso2_backend;
}