CVE-2022-50807: Concrete5 CMS XXE Vulnerability

CVE-2022-50807 Overview

Concrete5 CMS version 9.1.3 contains an XPath injection vulnerability that allows attackers to manipulate URL path parameters with malicious payloads. This web application vulnerability enables attackers to flood the system with crafted requests to potentially extract internal content paths and system information, posing a significant risk to organizations running vulnerable versions of the CMS platform.

Critical Impact

Attackers can exploit XPath injection to extract sensitive internal content paths and system information from vulnerable ConcreteCMS installations through network-based attacks requiring no authentication.

Affected Products

• ConcreteCMS version 9.1.3

Discovery Timeline

• 2026-01-13 - CVE CVE-2022-50807 published to NVD
• 2026-01-13 - Last updated in NVD database

Technical Details for CVE-2022-50807

Vulnerability Analysis

This XPath injection vulnerability (CWE-643) affects ConcreteCMS version 9.1.3 and stems from improper neutralization of user-supplied input within XPath queries. When attackers submit specially crafted URL path parameters containing XPath syntax, the application fails to properly sanitize or validate these inputs before incorporating them into XPath expressions used for XML document queries.

The vulnerability is network-exploitable and does not require authentication, making it accessible to remote attackers. Upon successful exploitation, attackers can manipulate the logic of XPath queries to extract data that should not be accessible, including internal content paths and potentially sensitive system configuration information stored in XML structures.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and improper handling of user-controlled data within XPath query construction. ConcreteCMS version 9.1.3 fails to implement proper sanitization routines for URL path parameters before they are concatenated into XPath expressions. This lack of input neutralization allows attackers to inject arbitrary XPath syntax that modifies the intended query behavior, enabling unauthorized data extraction from the underlying XML data stores.

Attack Vector

The attack vector is network-based (AV:N), requiring no user interaction or special privileges to exploit. Attackers craft malicious HTTP requests containing XPath injection payloads within URL path parameters. When the vulnerable ConcreteCMS instance processes these requests, the injected XPath syntax is executed against the XML document, allowing attackers to:

1. Extract internal content paths and navigation structures
2. Enumerate system information stored in XML configuration files
3. Potentially bypass access controls implemented through XPath-based queries
4. Flood the system with crafted requests to conduct information gathering at scale

The vulnerability mechanism involves manipulating XPath query logic through injection of operators and expressions that alter the query's selection criteria. Detailed technical information and proof-of-concept materials are available through the GitHub CVE PoC Repository and Exploit-DB #51144.

Detection Methods for CVE-2022-50807

Indicators of Compromise

• HTTP requests containing XPath special characters in URL path parameters such as ', ", [, ], /, //, |, and, or
• Unusual patterns of requests targeting XML-related endpoints or configuration paths
• Error messages in application logs indicating XPath parsing failures or syntax errors
• High volume of requests from single IP addresses probing various URL paths with injection payloads

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common XPath injection patterns in URL parameters
• Implement request logging and analysis for URL paths containing XPath syntax and operators
• Monitor for anomalous request patterns targeting ConcreteCMS instances, particularly focused on path enumeration
• Utilize SentinelOne Singularity Platform to detect suspicious web application behavior and injection attempts

Monitoring Recommendations

• Enable verbose logging on ConcreteCMS installations to capture full request details including URL parameters
• Configure alerting for repeated failed requests containing special characters in paths
• Monitor network traffic for patterns consistent with automated XPath injection scanning tools
• Review application error logs for XPath-related exceptions that may indicate exploitation attempts

How to Mitigate CVE-2022-50807

Immediate Actions Required

• Identify all ConcreteCMS installations running version 9.1.3 in your environment
• Implement WAF rules to filter and block requests containing XPath injection patterns
• Review access logs for evidence of prior exploitation attempts
• Consider temporarily restricting access to vulnerable instances until patches can be applied

Patch Information

Organizations should upgrade to a patched version of ConcreteCMS that addresses this XPath injection vulnerability. Visit the ConcreteCMS Download Page for the latest secure release. Additionally, consult the VulnCheck Advisory on XPath Injection for vendor-specific remediation guidance.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules specifically designed to block XPath injection payloads in URL parameters
• Implement network-level access controls to limit exposure of ConcreteCMS instances to trusted IP ranges only
• Configure input validation at the reverse proxy or load balancer level to reject requests with suspicious characters
• Enable rate limiting to reduce the impact of flooding attacks designed to extract information through repeated injection attempts

# Example WAF rule configuration for Apache ModSecurity
# Block common XPath injection patterns in URLs
SecRule REQUEST_URI "@rx (\[|\]|\/\/|\||\bor\b|\band\b|'|\")" \
    "id:1001,phase:1,deny,status:403,msg:'Potential XPath Injection Attempt'"