Grav CMS 1.7.48 suffers from a critical remote code execution vulnerability that allows unauthenticated attackers to 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 insecure deserialization within Grav's core or plugins, enabling attackers to inject and execute malicious PHP payloads remotely. Exploit code written in PHP has been published on Exploit-DB (EDB ID 52402), demonstrating how attackers can leverage this flaw to gain full control over the affected server. Although no active exploitation has been reported yet, the availability of exploit code significantly raises the threat level. The vulnerability affects all installations running version 1.7.48 and possibly earlier versions if unpatched. Exploitation does not require authentication or user interaction, making it highly dangerous. Successful exploitation can lead to complete system compromise, data exfiltration, website defacement, or use of the server as a pivot point for further attacks. Grav CMS users should prioritize patching or upgrading to a fixed version once released. In the interim, restricting access to the CMS backend, implementing web application firewalls (WAFs) with custom rules, and monitoring logs for suspicious PHP execution attempts are critical defensive measures.

For European organizations, this RCE vulnerability in Grav CMS poses a severe risk to the confidentiality, integrity, and availability of web assets. Organizations relying on Grav CMS for public-facing websites, intranet portals, or digital services may face unauthorized data disclosure, defacement, or complete server takeover. This could result in reputational damage, regulatory penalties under GDPR for data breaches, and operational disruptions. Attackers could leverage compromised servers to launch further attacks within corporate networks or as part of botnets. The ease of exploitation without authentication and the availability of exploit code increase the likelihood of targeted attacks or opportunistic exploitation. Sectors such as government, finance, healthcare, and media in Europe that use Grav CMS are particularly vulnerable. The impact extends to third-party service providers hosting Grav CMS sites, potentially affecting supply chain security. Prompt mitigation is essential to prevent exploitation and limit potential damage.

1. Immediately identify all Grav CMS instances running version 1.7.48 or earlier within your environment. 2. Apply official patches or upgrade to the latest secure version of Grav CMS as soon as they are released by the vendor. 3. If patches are not yet available, restrict access to Grav CMS administrative interfaces using IP whitelisting, VPNs, or strong authentication mechanisms. 4. Deploy web application firewalls (WAFs) with custom rules to detect and block suspicious PHP payloads or unusual HTTP requests targeting Grav CMS endpoints. 5. Monitor server and application logs for signs of exploitation attempts, such as unexpected PHP execution or anomalous requests. 6. Conduct regular security assessments and penetration testing focused on web applications running Grav CMS. 7. Educate web administrators and developers about the risks of this vulnerability and the importance of timely patching. 8. Consider isolating Grav CMS servers in segmented network zones to limit lateral movement if compromised. 9. Backup Grav CMS data and configurations regularly to enable rapid recovery in case of an incident. 10. Engage with Grav CMS community and security advisories for updates and best practices.