OS Command Injection in 4MOSAn GCB Doctor

4MOSAn GCB Doctor, developed by 4MOSAn Security Technology, contains an OS Command Injection vulnerability (CVE-2026-78211) due to an improperly removed ADOdb test page included in versions prior to 20260621. This vulnerability allows unauthenticated remote attackers to send crafted HTTP requests to the vulnerable test page, enabling the injection and execution of arbitrary OS-level commands on the affected server. Given the nature of the software, successful exploitation grants the attacker full control over the host environment. Defenders should prioritize patching or removing the insecure test files immediately.

Attack Chain

1. Attacker performs reconnaissance to identify instances of 4MOSAn GCB Doctor.
2. Attacker probes the web server for the presence of the known vulnerable ADOdb test page.
3. Attacker sends a crafted HTTP request to the discovered ADOdb test page path.
4. The input parameter within the request is passed unsanitized to a system shell.
5. The server process executes the attacker-supplied command with the privileges of the web service account.
6. Attacker confirms successful command injection through server responses or out-of-band callbacks.
7. Attacker performs post-exploitation activities, such as establishing persistence or exfiltrating data.

Impact

Successful exploitation of this vulnerability leads to unauthenticated remote code execution on the underlying server. This can result in complete system compromise, unauthorized access to sensitive configuration files, and potential pivot points into the internal network. No specific victim counts have been reported, but organizations utilizing 4MOSAn GCB Doctor versions prior to 20260621 are considered at high risk.

Recommendation

• Apply the security update to 4MOSAn GCB Doctor version 20260621 or later.
• If patching is not immediately feasible, identify and delete the ADOdb test page files from the web root to prevent exploitation.
• Enable web server access logging and audit requests targeting suspicious file paths associated with ADOdb test tools.
• Deploy the provided Sigma rule to detect attempts to reach the known vulnerable endpoint.