Source: cve@mitre.org
viewFile.php in the scm component of Gforge before 4.0 allows remote attackers to execute arbitrary commands via shell metacharacters in the file_name parameter.
Gforge versions prior to 4.0 are vulnerable to a critical remote command execution (RCE) vulnerability. Attackers can leverage the viewFile.php script to inject and execute arbitrary commands on the server by manipulating the file_name parameter, potentially leading to complete system compromise and data exfiltration.
Step 1: Payload Delivery: The attacker crafts a malicious URL targeting viewFile.php with a crafted file_name parameter. This parameter contains shell metacharacters and the desired command to execute (e.g., file_name=;id;).
Step 2: Request Processing: The user's web browser sends the crafted URL to the vulnerable Gforge server.
Step 3: Script Execution: The viewFile.php script receives the request and retrieves the value of the file_name parameter.
Step 4: Command Injection: The script, without proper sanitization, passes the attacker-controlled file_name value to a shell command (likely using a function like system(), exec(), or shell_exec()).
Step 5: Command Execution: The shell interprets the injected metacharacters and executes the attacker's command (e.g., id).
Step 6: Result Retrieval: The output of the executed command (e.g., the user ID) is likely returned to the attacker, potentially through the web server's response or by writing to a file accessible by the attacker.
The vulnerability stems from improper input validation and sanitization within the viewFile.php script of Gforge. Specifically, the script fails to properly sanitize the file_name parameter before passing it to a shell command. This allows an attacker to inject shell metacharacters (e.g., ;, |, &, $()) into the file_name parameter, effectively crafting a malicious command that the server executes. The root cause is a lack of input validation and command injection vulnerability. The script directly uses the user-supplied file_name without proper escaping or filtering, leading to the execution of attacker-controlled commands. This is a classic example of a command injection vulnerability.
While specific APT groups are not directly linked to this CVE, the ease of exploitation makes it a prime target for opportunistic attackers and botnets. This vulnerability could be used as an initial access vector for more sophisticated attacks. CISA KEV: Not listed.
Web server access logs: Look for suspicious requests to viewFile.php with unusual file_name parameters containing shell metacharacters (e.g., ;, |, &, $(), backticks).
Network traffic analysis: Examine HTTP requests for the same patterns as above. Use a Web Application Firewall (WAF) to detect and block malicious payloads.
File system monitoring: Monitor for the creation or modification of unexpected files, especially those created by the web server user.
Intrusion Detection System (IDS) signatures: Implement IDS rules to detect command injection attempts based on known exploit patterns.
Review web server error logs for unusual activity or errors related to command execution.
Upgrade to Gforge version 4.0 or later. This is the primary and most effective remediation.
Implement input validation and sanitization: Ensure that the file_name parameter is properly validated to prevent the injection of shell metacharacters. Use regular expressions or other methods to filter out or escape potentially malicious characters.
Use parameterized queries or prepared statements when interacting with the database, if applicable.
Implement a Web Application Firewall (WAF) to detect and block malicious requests.
Restrict the privileges of the web server user to the minimum necessary. This limits the impact of a successful exploit.
Regularly scan the system for vulnerabilities and apply security patches promptly.
Monitor system logs for suspicious activity.