Source: cve@mitre.org
Mongoose 2.8.0 and earlier allows remote attackers to obtain the source code for a web page by appending ::$DATA to the URI.
Mongoose versions 2.8.0 and earlier are vulnerable to a critical information disclosure flaw. This allows remote attackers to retrieve the source code of web pages by manipulating the URI, potentially exposing sensitive information like credentials, API keys, and application logic, leading to complete system compromise.
Step 1: Target Identification: The attacker identifies a Mongoose web server running a vulnerable version (2.8.0 or earlier).
Step 2: Crafting the Payload: The attacker constructs a malicious URI by appending ::$DATA to the end of a target file's path (e.g., /index.html::$DATA).
Step 3: Payload Delivery: The attacker sends an HTTP GET request containing the crafted URI to the Mongoose web server.
Step 4: Vulnerability Trigger: The Mongoose server processes the request, failing to properly sanitize the URI. The ::$DATA component is interpreted, leading to the server attempting to retrieve the raw source code.
Step 5: Information Disclosure: The server responds with the source code of the requested file, revealing sensitive information to the attacker.
The vulnerability stems from insufficient input validation and improper handling of URI requests within the Mongoose web server. Specifically, the server fails to properly sanitize the URI when processing requests for web page content. By appending ::$DATA to the end of a URI, an attacker can bypass the intended file access restrictions and force the server to return the raw source code of the requested file. This is likely due to a flaw in how Mongoose parses and interprets the URI, failing to recognize and block the ::$DATA component, which is then interpreted by the underlying file system as a request for the file's data stream, bypassing any access control mechanisms. The root cause is a lack of proper input validation and sanitization of the URI, allowing for a path traversal-like vulnerability.
While no specific APT groups are directly linked to exploiting this vulnerability, its simplicity and potential impact make it a likely target for various threat actors. This type of information disclosure is often a precursor to more sophisticated attacks. Not listed on CISA KEV.
Network Intrusion Detection Systems (NIDS) can be configured to detect requests containing ::$DATA in the URI.
Web Application Firewalls (WAFs) can be configured to block requests containing ::$DATA in the URI.
Review web server access logs for suspicious requests containing ::$DATA.
Monitor file access logs for unexpected access to sensitive files.
Upgrade to a patched version of Mongoose (2.8.1 or later).
Implement a Web Application Firewall (WAF) to filter malicious requests.
Review and harden web server configuration to restrict access to sensitive files.
Implement strict input validation and sanitization on all user-supplied data, including URIs.
Regularly scan for vulnerabilities using vulnerability scanners.