CVE-2025-3954 is a Server-Side Request Forgery (SSRF) vulnerability identified in ChurchCRM version 5.16.0, specifically within an unspecified functionality of the Referer Handler component. SSRF vulnerabilities allow an attacker to induce the server to make HTTP requests to arbitrary domains, potentially accessing internal resources or services that are otherwise inaccessible externally. In this case, the vulnerability can be exploited remotely without requiring authentication or user interaction, but the attack complexity is rated as high, indicating that exploitation requires significant effort or specific conditions. The vulnerability has been publicly disclosed, but no patch or vendor response has been provided to date. The CVSS 4.0 base score is 6.3 (medium severity), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, and limited impact primarily on integrity. The limited impact suggests that the SSRF may allow limited unauthorized interactions or information gathering but does not directly compromise confidentiality or availability. No known exploits are currently observed in the wild, but the public disclosure increases the risk of future exploitation attempts. The lack of vendor response and absence of patches means affected organizations must rely on mitigation strategies until an official fix is released.

For European organizations using ChurchCRM 5.16.0, this SSRF vulnerability poses a moderate risk. ChurchCRM is a customer relationship management system tailored for churches and religious organizations, which may hold sensitive personal data of congregants, including contact information and donation records. Exploitation could allow attackers to perform unauthorized internal network scans, access internal services, or leverage the server as a proxy for further attacks, potentially leading to data exposure or lateral movement within the network. Although the direct impact on confidentiality and availability is limited, the SSRF could be a stepping stone for more complex attacks, especially in environments where internal services lack proper segmentation or access controls. The medium severity rating and high attack complexity reduce the immediate threat level but do not eliminate risk, particularly given the public disclosure and lack of patch. European organizations with limited cybersecurity resources or outdated network segmentation may be more vulnerable to exploitation attempts.

1. Network Segmentation: Restrict outbound HTTP/HTTPS requests from the ChurchCRM server to only trusted external endpoints using firewall rules or proxy configurations. This limits the ability of SSRF to reach internal or sensitive network resources. 2. Input Validation and Filtering: Implement strict validation and sanitization of Referer header inputs or any user-controllable parameters that influence server requests to prevent injection of arbitrary URLs. 3. Disable or Restrict Referer Handler Functionality: If feasible, disable the vulnerable Referer Handler component or restrict its functionality until a patch is available. 4. Monitor and Log Outbound Requests: Enable detailed logging of outbound HTTP requests from the ChurchCRM server to detect unusual or unauthorized request patterns indicative of SSRF exploitation attempts. 5. Apply Web Application Firewall (WAF) Rules: Deploy WAF rules specifically designed to detect and block SSRF attack patterns targeting ChurchCRM or similar applications. 6. Incident Response Preparedness: Prepare for potential exploitation by establishing monitoring and response procedures focused on SSRF indicators and anomalous internal network activity. 7. Vendor Engagement: Continuously monitor for vendor updates or community patches and apply them promptly once available. 8. Alternative CRM Solutions: Consider migrating to alternative CRM platforms with active security maintenance if ChurchCRM support remains unresponsive.