CVE-2022-39986 in raspap-webgui
Summary
by MITRE • 08/01/2023
A Command injection vulnerability in RaspAP 2.8.0 thru 2.8.7 allows unauthenticated attackers to execute arbitrary commands via the cfg_id parameter in /ajax/openvpn/activate_ovpncfg.php and /ajax/openvpn/del_ovpncfg.php.
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Analysis
by VulDB Data Team • 08/24/2023
The vulnerability CVE-2022-39986 represents a critical command injection flaw within RaspAP versions 2.8.0 through 2.8.7, specifically affecting the OpenVPN configuration management functionality. This issue resides in the ajax/openvpn/activate_ovpncfg.php and ajax/openvpn/del_ovpncfg.php endpoints, where the cfg_id parameter is improperly validated and sanitized. The vulnerability allows unauthenticated attackers to inject malicious commands that will be executed with the privileges of the web server process, potentially leading to complete system compromise. The flaw stems from insufficient input validation and improper command construction when handling OpenVPN configuration identifiers, creating an avenue for arbitrary code execution without requiring authentication or prior access to the system.
The technical implementation of this vulnerability demonstrates a classic command injection weakness that maps to CWE-77, which specifically addresses the injection of commands into a command interpreter. The vulnerability occurs when user-supplied input from the cfg_id parameter is directly incorporated into system commands without proper sanitization or escaping mechanisms. Attackers can exploit this by crafting malicious input that includes shell metacharacters such as semicolons, pipes, or command substitution operators, which will be interpreted and executed by the underlying operating system. The affected RaspAP versions expose this vulnerability through their web interface, where OpenVPN configuration management is handled via AJAX endpoints, making it particularly dangerous as it can be exploited through standard web browser interactions without requiring specialized tools or elevated privileges.
The operational impact of CVE-2022-39986 extends beyond simple command execution, as it provides attackers with the ability to manipulate the entire OpenVPN infrastructure managed by RaspAP. Successful exploitation could enable attackers to modify or delete OpenVPN configurations, establish persistent backdoors, access network resources, or even gain root-level access to the underlying Raspberry Pi system. The unauthenticated nature of this vulnerability means that any attacker with network access to the affected system can exploit it, making it particularly dangerous in environments where RaspAP is deployed without proper network segmentation or firewall protection. This vulnerability directly aligns with ATT&CK technique T1059.001, which covers command and script interpreter usage, and T1068, which addresses exploit for privilege escalation, as the initial command injection can potentially lead to higher-level system compromise.
Mitigation strategies for CVE-2022-39986 must focus on immediate patching of affected RaspAP versions, with administrators upgrading to versions 2.8.8 or later where the vulnerability has been addressed through proper input validation and parameter sanitization. Network-level protections should include firewall rules that restrict access to the affected AJAX endpoints, particularly when these systems are exposed to untrusted networks. The implementation of proper input validation and output encoding should be enforced throughout the application, with all user-supplied parameters being rigorously validated against expected input patterns and sanitized before any system interactions occur. Additionally, implementing principle of least privilege for web server processes and conducting regular security audits of web applications can help prevent similar vulnerabilities from emerging in the future. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts targeting these specific endpoints.