Concrete CMS v9.4.8 Multiple Vulnerabilities

Remote code execution in Concrete CMS prior to version 9.4.8 stems from unsafe deserialization of PHP objects in the Express Entry List block configuration. An authenticated administrator can inject malicious serialized data through the columns parameter that executes arbitrary code when unserialized without validation. This allows attackers with admin privileges to achieve complete system compromise through stored object injection attacks.

Concrete CMS versions below 9.4.8 contain a cross-site request forgery vulnerability in the Anti-Spam Allowlist Group Configuration that allows authenticated administrators to modify security settings without valid CSRF token validation. An attacker with administrative privileges can exploit this to bypass security controls by manipulating the group_id parameter before token verification occurs. Public exploit code exists for this vulnerability, and a patch is available.

Stored XSS in Concrete CMS Legacy Form block below version 9.4.8 allows authenticated users with form creation permissions to inject malicious JavaScript into multiple-choice question options, which executes for all users viewing the affected form. Public exploit code exists for this vulnerability. Administrators should upgrade to version 9.4.8 or later to remediate the risk of session hijacking and data theft.

Stored XSS in Concrete CMS versions before 9.4.8 allows authenticated users with page editing permissions to inject malicious scripts through the Legacy form Question field, targeting high-privilege accounts. Public exploit code exists for this vulnerability, which requires user interaction to execute. A patch is available in version 9.4.8 and later.

Concrete CMS versions below 9.4.8 contain a stored XSS vulnerability in the search block where unencoded page names and content are rendered in search results, allowing authenticated administrators to inject malicious JavaScript that executes for other users. Public exploit code exists for this vulnerability, which requires high privileges and user interaction to exploit. The vulnerability affects confidentiality and integrity but not availability.

Stored XSS in Concrete CMS versions before 9.4.8 allows authenticated administrators to inject malicious scripts through the Switch Language block, affecting any site where a rogue admin account exists. Public exploit code is available for this vulnerability. A patch is available in version 9.4.8 and later.