CVE-2025-29891: Apache Camel Auth Bypass Vulnerability

CVE-2025-29891 Overview

CVE-2025-29891 is a bypass/injection vulnerability in Apache Camel that affects the framework's default incoming header filter mechanism. This vulnerability allows attackers to include Camel-specific headers through HTTP request parameters, which can alter the behavior of vulnerable Camel components such as camel-bean and camel-exec.

The vulnerability is particularly concerning for Camel applications that are directly connected to the internet via HTTP, as attackers can inject malicious parameters into HTTP requests that get translated into internal headers. These headers can be provided either as request parameters or as part of the HTTP request payload.

Critical Impact

Attackers can manipulate Camel component behavior through HTTP parameter injection, potentially leading to unauthorized actions in vulnerable routes using components like camel-bean or camel-exec.

Affected Products

• Apache Camel versions 4.10.0 to 4.10.1 (upgrade to 4.10.2)
• Apache Camel versions 4.8.0 to 4.8.4 (upgrade to 4.8.5)
• Apache Camel versions 3.10.0 to 3.22.3 (upgrade to 3.22.4)

Discovery Timeline

• March 12, 2025 - CVE-2025-29891 published to NVD
• April 2, 2025 - Last updated in NVD database

Technical Details for CVE-2025-29891

Vulnerability Analysis

This vulnerability stems from inadequate filtering of incoming HTTP parameters in Apache Camel's default header filter implementation. When HTTP requests are processed by Camel HTTP components, request parameters can be translated into internal Camel headers. The default filter fails to properly sanitize these parameters, allowing attackers to inject Camel-specific headers that should be restricted.

The vulnerability is related to CVE-2025-27636, sharing the same root cause and requiring the same fix. However, CVE-2025-27636 was initially assumed to only be exploitable through malicious HTTP headers, whereas CVE-2025-29891 demonstrates that exploitation is also possible via HTTP parameters, expanding the attack surface significantly.

Exploitation requires that the targeted Camel route uses particular vulnerable components. The attack leverages network-based access with no authentication required, though exploitation complexity is considered high due to the specific configuration requirements.

Root Cause

The root cause lies in Camel's default incoming header filter mechanism (CWE-164: Improper Neutralization of Internal Special Elements). The filter does not adequately restrict which headers can be set through incoming HTTP requests, allowing external input to influence internal Camel processing headers. This design flaw enables attackers to manipulate the behavior of downstream Camel components by injecting specially crafted parameters that translate into trusted internal headers.

Attack Vector

The attack is network-based and targets Camel applications exposed to the internet through HTTP endpoints. All known Camel HTTP components are vulnerable out of the box, including:

• camel-servlet
• camel-jetty
• camel-undertow
• camel-platform-http
• camel-netty-http

An attacker can craft HTTP requests with malicious parameters that, when processed by these components, get converted into internal Camel headers. These injected headers can then alter the execution flow of vulnerable components like camel-bean (which could invoke arbitrary methods) or camel-exec (which could execute system commands). The injection can occur through URL query parameters for GET requests or within the body payload for POST requests.

Detection Methods for CVE-2025-29891

Indicators of Compromise

• Unusual HTTP request parameters containing Camel-specific header names (e.g., parameters starting with Camel or org.apache.camel)
• Unexpected method invocations in camel-bean component logs
• Anomalous command executions traced to camel-exec component activity
• HTTP requests with parameter names matching internal Camel header patterns

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block HTTP requests containing Camel-specific parameter patterns
• Monitor application logs for unexpected Camel header values or component behaviors that deviate from normal operation
• Deploy network intrusion detection signatures to identify HTTP traffic with injection patterns targeting Camel header filters
• Audit Camel route configurations to identify routes using vulnerable components (camel-bean, camel-exec) exposed to HTTP endpoints

Monitoring Recommendations

• Enable detailed logging for all Camel HTTP components to capture incoming request parameters and resulting header translations
• Set up alerts for HTTP requests containing parameters that match Camel internal header naming conventions
• Monitor system call activity on servers running Camel applications with camel-exec components for unexpected command executions
• Track and baseline normal parameter patterns for exposed Camel endpoints to detect anomalous injection attempts

How to Mitigate CVE-2025-29891

Immediate Actions Required

• Upgrade Apache Camel to patched versions: 4.10.2 for 4.10.x LTS, 4.8.5 for 4.8.x LTS, or 3.22.4 for 3.x releases
• Identify and inventory all Camel applications exposed to the internet via HTTP endpoints
• Review Camel routes using camel-bean and camel-exec components for potential exposure
• Implement network segmentation to limit direct internet access to Camel HTTP endpoints where possible

Patch Information

Apache has released security patches addressing this vulnerability across all affected version branches. Users should upgrade to the following versions:

For detailed patch information, refer to the Apache Camel CVE-2025-29891 Security Advisory.

Workarounds

• Deploy a reverse proxy or WAF in front of Camel HTTP endpoints to filter out suspicious request parameters before they reach the application
• Implement custom header filtering by overriding the default Camel header filter to explicitly block Camel-specific headers from external sources
• Restrict network access to Camel HTTP endpoints using firewall rules, limiting exposure to trusted networks only
• Disable or remove unused vulnerable components (camel-bean, camel-exec) from routes exposed to HTTP endpoints

# Example: Configure WAF rule to block Camel-specific parameters (ModSecurity)
# Add to your ModSecurity configuration
SecRule ARGS_NAMES "@rx ^(Camel|org\.apache\.camel)" \
    "id:100001,phase:1,deny,status:403,log,msg:'Blocked potential Camel header injection attempt'"