Source: cve@mitre.org
Mongoose 2.8.0 and earlier allows remote attackers to obtain the source code for a web page by appending a / (slash) character to the URI.
Mongoose versions 2.8.0 and earlier are vulnerable to a critical information disclosure flaw. Attackers can remotely retrieve the source code of web pages by appending a forward slash ('/') to the URL, potentially revealing sensitive information like credentials, application logic, and internal configurations. This vulnerability allows for a complete compromise of the web application and underlying server infrastructure.
Step 1: Target Identification: The attacker identifies a web server running Mongoose version 2.8.0 or earlier.
Step 2: URI Construction: The attacker crafts a malicious URL by appending a forward slash ('/') to the end of a known valid URI (e.g., http://target.com/index.html/).
Step 3: Request Submission: The attacker sends the crafted URL to the vulnerable Mongoose server.
Step 4: Server Processing: The Mongoose server receives the request and attempts to process it.
Step 5: Vulnerability Trigger: Due to the missing input validation, the server misinterprets the request, potentially leading to the source code of the requested resource being served instead of the expected output.
Step 6: Information Disclosure: The attacker receives the source code of the requested web page, potentially revealing sensitive information.
The vulnerability stems from an improper handling of URI parsing within the Mongoose web server. Specifically, the server fails to correctly sanitize or validate the URI before attempting to serve the requested resource. When a forward slash ('/') is appended to a valid URI, the server's logic likely misinterprets the request, potentially leading it to serve the source code of the requested file instead of executing it. This could be due to a missing check or a flawed implementation of the file serving logic. The root cause is a lack of input validation and sanitization of the URI, allowing for a simple manipulation to bypass security checks and expose sensitive information. The server likely attempts to read the file, but the appended slash causes it to misinterpret the file path, leading to the source code being served instead of the compiled or interpreted output.
While no specific APTs are directly linked to this CVE, the ease of exploitation makes it a target for a wide range of actors, including opportunistic attackers and those seeking initial access. This vulnerability could be used as a stepping stone for more sophisticated attacks. CISA KEV: Not Listed
Network Intrusion Detection Systems (NIDS) can be configured to detect requests with trailing slashes, especially to known web application paths (e.g., /index.html/, /login.php/).
Web Application Firewalls (WAFs) can be configured to block requests containing trailing slashes or other suspicious URI patterns.
Log analysis of web server access logs for requests with trailing slashes. Look for unusual patterns, especially if the server is serving source code files.
File integrity monitoring to detect changes to critical web application files.
Upgrade to a patched version of Mongoose (version 2.8.1 or later).
Implement input validation and sanitization to properly handle URIs, ensuring that trailing slashes are correctly processed and do not lead to information disclosure.
Configure a Web Application Firewall (WAF) to filter out malicious requests, including those with trailing slashes.
Review and harden the web server configuration to minimize the attack surface.
Regularly scan for vulnerabilities and apply security patches promptly.
Implement a Content Security Policy (CSP) to mitigate the impact of potential cross-site scripting (XSS) vulnerabilities that could be chained with this information disclosure.