Source: cve@mitre.org
Directory traversal vulnerability on the HOT HOTBOX router with software 2.1.11 allows remote attackers to read arbitrary files via a .. (dot dot) in a URI, as demonstrated by a request for /etc/passwd.
A critical directory traversal vulnerability exists in the HOT HOTBOX router (software version 2.1.11), allowing remote attackers to read sensitive files. This vulnerability enables attackers to gain unauthorized access to system files, potentially leading to complete system compromise and data exfiltration.
Step 1: Payload Delivery: The attacker crafts a malicious HTTP GET request targeting the vulnerable router. The request includes a URI containing a directory traversal payload, such as '/../../etc/passwd'.
Step 2: Request Processing: The router's web server receives the malicious HTTP request.
Step 3: Path Interpretation: The web server's file handling logic interprets the URI path. Due to the lack of input validation, the '..' sequences are not filtered or blocked.
Step 4: File Access: The server attempts to access the file specified by the modified path, which now points to a file outside the intended web server directory (e.g., /etc/passwd).
Step 5: Data Retrieval: The server successfully reads the contents of the targeted file (e.g., /etc/passwd) and returns it in the HTTP response.
The vulnerability stems from insufficient input validation in the router's web server. Specifically, the server fails to properly sanitize user-supplied input within the URI path. The server processes the URI without adequately checking for or blocking the use of '..' (dot-dot) sequences. This allows an attacker to craft a malicious URI that navigates outside the intended directory structure. The lack of proper path normalization allows the attacker to traverse the file system and access sensitive files like /etc/passwd, /etc/shadow, or potentially configuration files containing sensitive credentials. The root cause is a missing or inadequate input validation mechanism, coupled with a failure to perform path canonicalization before accessing files. This allows for relative path traversal to access files outside the web server's intended root directory.
While no specific APT groups are directly linked to this vulnerability, the nature of directory traversal makes it a common attack vector. It is a low-hanging fruit that can be used by various actors. The vulnerability's age and the type of device suggest it is unlikely to be a primary target for sophisticated APTs. Not on CISA KEV.
Monitor web server logs for suspicious URI patterns containing '..' sequences.
Implement network intrusion detection systems (IDS) with signatures specifically designed to detect directory traversal attempts.
Analyze HTTP request logs for requests targeting sensitive files like /etc/passwd, /etc/shadow, or configuration files.
Perform regular vulnerability scans to identify vulnerable devices.
Monitor file access logs for unexpected access to sensitive system files.
Upgrade the HOT HOTBOX router to a patched version (if available).
Implement robust input validation to sanitize all user-supplied input, including URI paths. This should involve filtering or blocking '..' sequences and other potentially malicious characters.
Perform path canonicalization to resolve relative paths and prevent directory traversal.
Restrict access to sensitive files and directories. Ensure that the web server process runs with the least privileges necessary.
Implement a web application firewall (WAF) to filter malicious requests.
Regularly update the router's firmware and security patches.
Consider replacing the vulnerable router with a more secure alternative.