CVE-2025-50567: Saurus CMS Community Edition RCE Flaw

CVE-2025-50567 Overview

Saurus CMS Community Edition 4.7.1 contains a critical vulnerability in the custom DB::prepare() function, which uses preg_replace() with the deprecated /e (eval) modifier to interpolate SQL query parameters. This dangerous coding practice leads to injection of user-controlled SQL statements, potentially enabling arbitrary PHP code execution on affected systems.

Critical Impact

This vulnerability allows unauthenticated remote attackers to achieve arbitrary PHP code execution through SQL injection, potentially leading to complete system compromise with full access to confidential data, system integrity, and availability.

Affected Products

• Saurus CMS Community Edition 4.7.1

Discovery Timeline

• 2025-08-19 - CVE-2025-50567 published to NVD
• 2025-08-20 - Last updated in NVD database

Technical Details for CVE-2025-50567

Vulnerability Analysis

This vulnerability represents a severe security flaw arising from the use of deprecated PHP functionality. The DB::prepare() function in Saurus CMS utilizes preg_replace() with the /e modifier, which was deprecated in PHP 5.5.0 and removed in PHP 7.0.0 due to its inherent security risks. When the /e modifier is used, the replacement string is evaluated as PHP code after substitution, creating a direct path from user input to code execution.

The vulnerability is classified under CWE-89 (SQL Injection), though its impact extends beyond traditional SQL injection due to the PHP code execution component. An attacker can craft malicious input that, when processed through the vulnerable preg_replace() call, executes arbitrary PHP code on the server.

Root Cause

The root cause stems from insecure coding practices in the database abstraction layer. The DB::prepare() function was designed to sanitize and interpolate SQL query parameters but implemented using preg_replace() with the dangerous /e eval modifier. This modifier treats the replacement string as PHP code, meaning any attacker-controlled data that reaches this function can potentially be executed as PHP code. Modern PHP applications should use preg_replace_callback() instead, which provides the same functionality without the code execution risk.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests containing malicious payloads to any application endpoint that processes user input through the vulnerable DB::prepare() function. The payload would be constructed to escape the SQL context and inject PHP code that gets evaluated by the /e modifier.

The vulnerability mechanism involves manipulating input parameters passed to database queries. When these parameters reach the DB::prepare() function, the preg_replace() with /e modifier evaluates attacker-controlled strings as PHP code, enabling remote code execution. For detailed technical analysis, refer to the GitHub CVE Analysis.

Detection Methods for CVE-2025-50567

Indicators of Compromise

• Unusual HTTP requests containing PHP code syntax such as eval(), system(), exec(), or backtick operators in query parameters
• Web server logs showing requests with encoded PHP functions or shell commands in URL parameters
• Unexpected outbound network connections from the web server process
• New or modified PHP files in the Saurus CMS installation directory
• Database query logs containing malformed or suspicious SQL statements with PHP code fragments

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block requests containing PHP code patterns in input fields
• Implement intrusion detection signatures for common PHP code execution patterns such as preg_replace exploitation attempts
• Monitor application logs for SQL errors that indicate injection attempts or malformed queries
• Utilize SentinelOne's behavioral AI to detect anomalous process spawning from web server processes

Monitoring Recommendations

• Enable verbose logging for the Saurus CMS application and database connections
• Monitor file integrity for the CMS installation directory to detect unauthorized modifications
• Implement network monitoring for unusual outbound connections from the web server
• Configure alerting for any new PHP process executions that originate from web requests

How to Mitigate CVE-2025-50567

Immediate Actions Required

• Immediately audit all instances of Saurus CMS Community Edition 4.7.1 in your environment
• Consider taking affected systems offline or placing them behind strict network access controls until patched
• Implement WAF rules to filter requests containing potential PHP code injection patterns
• Review web server and application logs for signs of prior exploitation attempts
• Restrict network access to administrative interfaces of the CMS

Patch Information

As of the last NVD update on 2025-08-20, no official patch information has been published. Organizations should monitor the Saurus Security Overview and Saurused Security Resource for vendor updates regarding this vulnerability. Given the critical severity and lack of available patches, organizations should prioritize implementing compensating controls.

Workarounds

• Deploy a web application firewall with rules specifically blocking PHP code patterns in request parameters
• If PHP version permits, upgrade to PHP 7.0 or later where the /e modifier is removed entirely, causing the vulnerable code to fail rather than execute
• Implement input validation at the network perimeter to sanitize or reject requests containing suspicious patterns
• Consider replacing the vulnerable DB::prepare() function with a secure implementation using preg_replace_callback() or parameterized queries if source code access is available
• Isolate affected systems in a network segment with restricted access and egress filtering

As no verified mitigation configuration has been provided by the vendor, organizations should consult the GitHub CVE Analysis for additional technical guidance on implementing custom mitigations.