User Agent Fuzzer

Check for differences in response based on fuzzed User Agent (eg. mobile sites, access as a Search Engine Crawler). Compares the response statuscode and the hashcode of the response body with the original response.

This detector identifies endpoints that respond differently based on the User-Agent header, which may indicate hidden functionality or different code paths for mobile browsers or search engine crawlers. While not directly exploitable, these differences can expose administrative interfaces, debugging features, or less-tested code paths that attackers can target. Crawlers or mobile-specific endpoints often have reduced security controls, making them attractive targets for reconnaissance and subsequent attacks.

Ensure all User-Agent variants receive consistent security controls. Avoid exposing sensitive functionality through crawler-specific or mobile-specific endpoints. Implement uniform authentication and authorization checks regardless of the client type. Review any differences in responses to ensure they do not leak sensitive information or bypass security mechanisms.