Web Cache Exploitation Techniques and Discrepancies

This document is a technical report that outlines the mechanisms of web cache exploitation through URL parsing discrepancies. It describes how web caches function by fingerprinting requests and mapping keys to static responses. The report explains the importance of understanding cache behaviors, particularly in the context of Content Delivery Networks (CDNs) like CloudFlare and Akamai. It details techniques for exploiting these discrepancies, leading to web cache poisoning and deception, which can result in unauthorized access to sensitive information. The report also discusses various delimiters used by different web servers and frameworks, such as Spring and Rails, which can influence the parsing of URLs. Furthermore, it provides methods for detecting inconsistencies in URL normalization processes between cache servers and origin servers. The document concludes with recommendations for defense mechanisms against these types of attacks, emphasizing the need for careful analysis of cache rules and key generation methods.