Source: cve@mitre.org
Directory traversal vulnerability in quiz.cgi for Mike Spice Quiz Me! before 0.6 allows remote attackers to write arbitrary files via .. (dot dot) sequences in the quiz parameter.
Mike Spice Quiz Me! versions prior to 0.6 are vulnerable to a critical directory traversal attack. This allows a remote attacker to write arbitrary files to the server, potentially leading to remote code execution (RCE) and complete system compromise. The vulnerability stems from insufficient input validation in the quiz.cgi script, enabling attackers to manipulate file paths.
Step 1: Payload Preparation: The attacker crafts a malicious quiz file containing arbitrary content, including malicious code (e.g., PHP code, shell commands).
Step 2: Path Manipulation: The attacker constructs a URL with a crafted quiz parameter containing .. sequences to navigate to a target directory (e.g., the web root or a directory where executable files are stored).
Step 3: File Write: The attacker submits the crafted URL to quiz.cgi. The script, failing to validate the input, interprets the quiz parameter, including the .. sequences, and attempts to write the malicious quiz file to the specified target location.
Step 4: Code Execution (if applicable): If the attacker successfully writes the malicious file to a location where it can be executed (e.g., the web root), they can then trigger the execution of the malicious code by accessing the file via a web browser.
The vulnerability lies within the quiz.cgi script's handling of the quiz parameter. The script fails to properly sanitize user-supplied input, specifically the quiz parameter, allowing attackers to inject .. (dot-dot) sequences. This manipulation allows attackers to traverse the server's directory structure and write files to arbitrary locations. The root cause is a lack of input validation and path sanitization. Specifically, the script does not check for or remove .. sequences or validate the target file path before writing the quiz data. This allows an attacker to craft a malicious quiz file and write it to a location of their choosing, potentially overwriting critical system files or web application files, leading to RCE.
Due to the age of the vulnerability, it's unlikely to be directly associated with specific, modern APT groups. However, any attacker with basic skills could exploit this. The simplicity of the exploit makes it a prime target for opportunistic attacks. CISA KEV status: Not Listed
Web server access logs: Examine logs for suspicious requests to quiz.cgi containing .. sequences in the quiz parameter.
File system monitoring: Monitor for unexpected file creation or modification, especially in sensitive directories (e.g., web root, configuration files).
Intrusion Detection Systems (IDS): Implement rules to detect attempts to exploit the directory traversal vulnerability, looking for .. sequences in HTTP requests targeting quiz.cgi.
Network traffic analysis: Analyze network traffic for requests containing the quiz parameter with suspicious values, such as path traversal attempts.
File Integrity Monitoring (FIM): Use FIM tools to monitor critical system files for unauthorized changes.
Upgrade to Mike Spice Quiz Me! version 0.6 or later.
Implement input validation: Ensure that the quiz.cgi script properly sanitizes the quiz parameter, removing or encoding .. sequences and validating the target file path.
Restrict file write permissions: Configure the web server to limit the directories where the quiz.cgi script can write files. This can prevent attackers from writing to critical system files.
Use a Web Application Firewall (WAF): Deploy a WAF to filter malicious requests, including those attempting directory traversal attacks.
Regularly scan for vulnerabilities: Use vulnerability scanners to identify and remediate known vulnerabilities in web applications and servers.
Implement the principle of least privilege: Run the web server and associated scripts with the minimum necessary privileges.