CVE-2024-27623 identifies a Server-Side Template Injection (SSTI) vulnerability in CMS Made Simple version 2.2.19, a popular open-source content management system. The vulnerability resides in the Design Manager module, specifically when editing the Breadcrumbs component. SSTI vulnerabilities occur when user-supplied input is improperly sanitized and subsequently processed by a server-side template engine, allowing attackers to inject and execute arbitrary code on the server. In this case, exploitation requires an authenticated user with high privileges (PR:H) and user interaction (UI:R), indicating that an attacker must have access to the CMS backend and actively perform the injection. The vulnerability impacts confidentiality, integrity, and availability to a limited degree (C:L/I:L/A:L), as indicated by the CVSS vector, but the scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. No public exploits have been reported yet, and no patches are currently linked, suggesting that remediation may require vendor updates or configuration changes. The CWE-1336 classification corresponds to improper input validation in template engines, a common cause of SSTI. This vulnerability could allow attackers to execute arbitrary commands or code on the web server, potentially leading to data leakage, defacement, or further compromise of the hosting environment.

For European organizations, this vulnerability poses a moderate risk primarily to those using CMS Made Simple 2.2.19 for their web presence or internal portals. Successful exploitation could lead to unauthorized code execution, enabling attackers to access sensitive data, modify website content, or disrupt services. Given the requirement for high privileges and user interaction, the attack surface is somewhat limited to insiders or compromised accounts, but the potential damage remains significant in environments where the CMS is critical. Organizations in sectors such as government, education, and SMEs that rely on CMS Made Simple for content management may face reputational damage, regulatory scrutiny under GDPR if personal data is exposed, and operational downtime. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability becomes widely known.

To mitigate this vulnerability, European organizations should first restrict access to the Design Manager interface to only trusted, high-privilege users and enforce strong authentication mechanisms such as multi-factor authentication (MFA). Until an official patch is released, administrators should audit and sanitize all template inputs, particularly those related to Breadcrumbs editing, to prevent injection of malicious code. Implementing web application firewalls (WAFs) with rules targeting SSTI patterns can provide additional protection. Regularly monitoring logs for unusual template rendering or backend errors can help detect attempted exploitation. Organizations should also maintain an inventory of CMS versions in use and plan timely upgrades once patches become available. Educating administrators about the risks of SSTI and enforcing the principle of least privilege will reduce the likelihood of successful exploitation.