CVE-2025-15148 identifies a code injection vulnerability in CmsEasy, a content management system widely used for website backend management. The vulnerability resides in the savetemp_action function located in /lib/admin/template_admin.php, which handles backend template management. Specifically, the flaw allows an attacker to manipulate the content/tempdata parameter to inject and execute arbitrary code on the server. This attack vector is remote and does not require user interaction, but it does require the attacker to have high privileges (PR:H), indicating that some form of authentication or elevated access is necessary before exploitation. The vulnerability impacts confidentiality, integrity, and availability, as arbitrary code execution can lead to data theft, unauthorized changes, or service disruption. The CVSS 4.0 score is 5.1 (medium severity), reflecting the moderate ease of exploitation combined with the privilege requirement and limited scope of impact. The vendor was notified early but did not respond or provide a patch, and no public exploits have been observed in the wild yet. This lack of vendor response increases the risk as organizations must rely on their own mitigations. The vulnerability affects CmsEasy versions 7.7.0 through 7.7.7, which should be considered vulnerable until patched or mitigated. Given the backend nature of the flaw, it is likely to impact administrative users and systems managing website templates, which are critical for site integrity and operation.

For European organizations, the impact of CVE-2025-15148 can be significant, especially for those relying on CmsEasy for website or content management. Successful exploitation could lead to unauthorized code execution on web servers, allowing attackers to steal sensitive data, deface websites, implant malware, or disrupt services. This could damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR breaches), and cause operational downtime. The requirement for high privileges limits the attack surface but insider threats or compromised credentials could enable exploitation. Sectors such as government, finance, healthcare, and media in Europe that use CmsEasy are particularly vulnerable. Additionally, the lack of vendor response and patches increases exposure time, raising the risk of future exploitation. The medium CVSS score indicates moderate risk, but the potential for code injection elevates the severity of consequences if exploited.

European organizations should take immediate steps to mitigate this vulnerability: 1) Restrict access to the backend template management interface to trusted administrators only, ideally via IP whitelisting or VPN. 2) Implement strong authentication and monitor for unusual login activities to prevent privilege escalation or credential compromise. 3) Conduct code audits or apply manual input validation and sanitization on the content/tempdata parameter if possible. 4) Deploy web application firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting the vulnerable function. 5) Monitor logs for anomalous behavior related to template management actions. 6) Engage with the CmsEasy community or security forums for any unofficial patches or workarounds. 7) Prepare incident response plans in case of exploitation. 8) Consider isolating or segmenting the CMS environment to limit lateral movement. Since no official patch is available, these compensating controls are critical until a vendor fix is released.