Regular Expression Attack Technique On ReDoS Vulnerability

Regular expressions, or regexes, have become an integral part of modern software development, seamlessly woven into the fabric of countless applications. From validating user input in web forms to parsing complex log files for data analysis, regexes are employed across a vast spectrum of tasks. Their ability to precisely define and match patterns within text makes them invaluable tools for tasks ranging from simple data extraction to sophisticated security measures. However, this widespread reliance on regexes also introduces a significant security vulnerability: ReDoS (Regular Expression Denial of Service) attacks. These attacks exploit the inherent complexity of regex matching by crafting malicious input that triggers an exponentially long processing time, effectively bringing the application to a standstill. The potential for ReDoS attacks highlights the crucial need for developers to exercise extreme caution when designing and implementing regex-based components within their applications. This paper explores the inherent ambiguity of regular expressions, fuzzing with static analysis and proposes a novel fuzzing technique to generate effective attack patterns. By analyzing the potential interpretations of ambiguous regex constructs, our method identifies and exploits weaknesses in software implementations that rely on regex for input validation. The proposed fuzzing algorithm generates test cases that systematically explore the ambiguity space, maximizing the likelihood of uncovering vulnerabilities related to unexpected regex behavior. This approach aims to enhance software security by proactively detecting and mitigating potential attack vectors stemming from the misinterpretation of regular expression patterns.