How to protect against regex denial-of-service (ReDoS) attacks

The tutorial provides a comprehensive guide on protecting applications from regular expression denial-of-service (ReDoS) attacks, which exploit vulnerabilities in regex engines to cause systems to crash by consuming excessive resources. It explains the mechanics of regular expressions, highlighting how certain patterns can lead to catastrophic backtracking and result in exponential execution times. The text offers strategies to mitigate these vulnerabilities, such as reducing the number of combinations and controlling backtracking using techniques like atomic groups and lookahead assertions. The tutorial emphasizes the importance of understanding regex engine behavior to write efficient and secure regular expressions, especially in environments like Node.js, where single-threaded event loops are more susceptible to such attacks.