Grav CMS version 1.7.48 suffers from a critical Remote Code Execution vulnerability that allows attackers to remotely execute arbitrary PHP code on the server hosting the CMS. Grav CMS is a flat-file content management system widely used for building websites without a traditional database backend. The vulnerability likely stems from improper input validation or unsafe deserialization, enabling attackers to inject and execute malicious PHP code. The presence of publicly available exploit code in PHP significantly lowers the barrier for attackers to exploit this vulnerability. Since the exploit does not require authentication or user interaction, any publicly accessible Grav CMS instance running the vulnerable version is at immediate risk. Successful exploitation can lead to full system compromise, including data theft, website defacement, or pivoting to internal networks. Despite the critical severity, no official patches or security advisories have been linked in the provided information, indicating that organizations must rely on temporary mitigations and monitoring until a fix is released. The lack of CVSS score is mitigated by the critical severity tag and the nature of the vulnerability. This exploit represents a severe threat to web infrastructure relying on Grav CMS 1.7.48 or earlier.

For European organizations, the impact of this RCE vulnerability in Grav CMS 1.7.48 is significant. Many small to medium enterprises, public institutions, and private websites use Grav CMS due to its simplicity and flat-file architecture. Exploitation could lead to unauthorized access to sensitive data, including personal data protected under GDPR, resulting in legal and financial repercussions. The ability to execute arbitrary code remotely can allow attackers to deploy ransomware, steal credentials, or use compromised servers as a foothold for further attacks within corporate networks. Public sector websites and critical infrastructure that rely on Grav CMS could face service outages or defacement, damaging public trust and operational continuity. The availability of exploit code increases the likelihood of widespread attacks, especially targeting less-secured or unpatched systems. The absence of patches means organizations must act quickly to mitigate risk. Overall, the threat poses a high risk to confidentiality, integrity, and availability of affected systems across Europe.

European organizations should immediately audit their web infrastructure to identify any instances of Grav CMS, particularly version 1.7.48 or earlier. Until an official patch is released, organizations should consider the following mitigations: 1) Restrict access to Grav CMS administrative interfaces using IP whitelisting or VPNs to reduce exposure. 2) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious PHP payloads or unusual HTTP requests targeting Grav CMS endpoints. 3) Disable or restrict PHP execution permissions in directories used by Grav CMS if feasible. 4) Monitor web server logs and Grav CMS logs for signs of exploitation attempts, such as unexpected PHP code execution or anomalous requests. 5) Isolate Grav CMS servers from critical internal networks to limit lateral movement if compromised. 6) Prepare for rapid patch deployment once an official fix is available by subscribing to Grav CMS security advisories. 7) Educate web administrators about the risks and signs of exploitation. These targeted steps go beyond generic advice by focusing on immediate risk reduction and detection in the absence of a patch.