CVE-2025-12140: Insecure redirectToUrl RCE Vulnerability

CVE-2025-12140 Overview

CVE-2025-12140 is a critical Expression Language (EL) injection vulnerability affecting an application's redirectToUrl mechanism. The vulnerability exists because the application incorrectly processes the value of the redirectUrlParameter parameter, interpreting user-supplied input as a Java expression. This allows an unauthenticated attacker to perform arbitrary code execution by crafting malicious expressions that are evaluated by the server.

Critical Impact

Unauthenticated remote attackers can achieve arbitrary code execution by injecting malicious Java expressions through the redirectUrlParameter parameter, potentially leading to complete system compromise.

Affected Products

• Application versions prior to wu#2016.1.5513#0#20251014_113353

Discovery Timeline

• 2025-11-27 - CVE-2025-12140 published to NVD
• 2025-12-01 - Last updated in NVD database

Technical Details for CVE-2025-12140

Vulnerability Analysis

This vulnerability is classified as CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code, also known as 'Eval Injection'). The core issue stems from the application's redirect functionality treating user-controlled input as executable code rather than data.

When a user supplies a value to the redirectUrlParameter, the application fails to properly sanitize or validate this input before passing it to a Java expression evaluator. This means that instead of treating the parameter as a simple URL string, the application interprets special syntax within the parameter as Java Expression Language (EL) statements and executes them in the server context.

The network-accessible nature of this vulnerability combined with the lack of authentication requirements makes it particularly dangerous. An attacker needs no prior access or credentials to exploit this flaw—they simply need to craft a malicious HTTP request containing EL injection syntax within the redirect parameter.

Root Cause

The root cause is the unsafe handling of user input within the redirectToUrl mechanism. The application's design flaw allows raw user input from the redirectUrlParameter to be evaluated as Java expression code without proper input validation, sanitization, or contextual encoding. This violates secure coding principles that mandate treating all external input as untrusted data.

Attack Vector

The attack is conducted remotely over the network. An attacker crafts an HTTP request containing malicious Java Expression Language syntax within the redirectUrlParameter. When the application processes this request, it evaluates the attacker-controlled expression, executing arbitrary Java code on the server with the application's privileges.

The exploitation requires no user interaction and no authentication, making it accessible to any network-connected attacker who can reach the vulnerable endpoint. Successful exploitation results in complete compromise of confidentiality, integrity, and availability of the affected system.

For detailed technical information about this vulnerability, refer to the CERT Security Post on CVE-2025-12140.

Detection Methods for CVE-2025-12140

Indicators of Compromise

• Unusual HTTP requests containing Java Expression Language syntax (e.g., ${...} or #{...} patterns) in URL redirect parameters
• Unexpected process spawning or command execution originating from the web application process
• Web server logs showing requests to redirect endpoints with encoded or obfuscated payload strings
• Network connections to unknown external hosts initiated by the application server

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing EL injection patterns in redirect parameters
• Monitor application logs for requests with suspicious characters or patterns typical of expression injection attacks
• Deploy intrusion detection signatures to identify exploitation attempts targeting the redirectUrlParameter
• Utilize SentinelOne's Singularity Platform for behavioral detection of post-exploitation activities such as code execution and lateral movement

Monitoring Recommendations

• Enable detailed access logging on web servers to capture full request URIs and parameters
• Implement alerting for any process execution events spawned by the web application service account
• Monitor for outbound network connections from the application server that deviate from normal baseline behavior
• Configure SIEM rules to correlate multiple failed or suspicious redirect requests from the same source

How to Mitigate CVE-2025-12140

Immediate Actions Required

• Upgrade immediately to version wu#2016.1.5513#0#20251014_113353 or later where this issue has been fixed
• If immediate patching is not possible, restrict network access to the affected application to trusted sources only
• Implement WAF rules to block requests containing EL injection patterns in the redirectUrlParameter
• Review application logs for evidence of exploitation attempts prior to patching

Patch Information

The vendor has released a security patch addressing this vulnerability. The fix is included in version wu#2016.1.5513#0#20251014_113353. Organizations should prioritize deploying this update to all affected systems immediately. For additional details, consult the CERT Security Post on CVE-2025-12140.

Workarounds

• Deploy a web application firewall configured to sanitize or block requests containing Java Expression Language patterns
• Implement network segmentation to limit exposure of the vulnerable application to untrusted networks
• Disable or restrict access to the redirect functionality if not business-critical
• Apply strict input validation at the network perimeter using a reverse proxy to filter malicious patterns

# Example WAF rule pattern to block EL injection attempts
# Block requests containing ${...} or #{...} patterns in redirect parameters
# Consult your specific WAF documentation for implementation syntax
# Pattern: \$\{.*\}|\#\{.*\}