CVE-2021-44935 in glFusion
Summary
by MITRE • 12/14/2021
glFusion CMS v1.7.9 is affected by an arbitrary user impersonation vulnerability in /public_html/comment.php. The attacker can complete the attack remotely without interaction.
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Analysis
by VulDB Data Team • 12/16/2021
The vulnerability identified as CVE-2021-44935 affects glFusion CMS version 1.7.9 and represents a critical arbitrary user impersonation flaw located within the comment.php script. This vulnerability allows attackers to assume the identity of any user within the system without requiring any user interaction or authentication. The flaw exists in the application's permission handling mechanism where the system fails to properly validate user credentials or session tokens when processing comment-related requests. The vulnerability is particularly concerning because it operates entirely remotely and can be exploited without any prior access to valid user credentials or session information. The attack vector specifically targets the comment.php endpoint which serves as a critical interface for user-generated content within the CMS framework.
The technical implementation of this vulnerability stems from insufficient input validation and improper session management within the glFusion CMS codebase. When users submit comments or interact with comment-related functionality, the system should verify that the requesting user has appropriate permissions to perform the action. However, the flaw allows malicious actors to manipulate parameters or headers that control user identification, effectively bypassing authentication mechanisms. This type of vulnerability falls under the Common Weakness Enumeration category CWE-287, which addresses improper handling of authentication tokens and credentials. The vulnerability enables attackers to perform actions as if they were any registered user in the system, potentially including administrative functions if the targeted user has elevated privileges.
The operational impact of this vulnerability extends beyond simple user impersonation, as it can lead to complete system compromise depending on the privileges of the targeted users. An attacker can exploit this vulnerability to post malicious comments, modify content, access restricted areas, or potentially escalate privileges if they can target an administrator account. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring physical access to the system or any prior knowledge of valid user accounts. This vulnerability directly maps to the ATT&CK technique T1078 which covers valid accounts and privilege escalation through legitimate user credentials. The vulnerability's persistence and remote exploitability make it particularly dangerous for organizations relying on glFusion CMS for content management, as it can remain undetected while attackers operate under false identities.
Mitigation strategies for CVE-2021-44935 should prioritize immediate patching of the glFusion CMS to version 1.7.10 or later, which contains the necessary security fixes for this vulnerability. Organizations should also implement network-level controls such as web application firewalls that can detect and block malicious requests targeting the comment.php endpoint. Additional security measures include monitoring for unusual comment activity patterns, implementing stricter input validation, and ensuring that all user sessions are properly validated before granting access to sensitive functions. The vulnerability highlights the importance of proper access control implementation and the need for comprehensive security testing of all user-facing interfaces. Security teams should also conduct thorough audits of their CMS installations to identify any other potential vulnerabilities in the same codebase or related components. Organizations should consider implementing multi-factor authentication for administrative accounts and regularly review user permissions to minimize potential damage from successful exploitation attempts.