AWS WAF ADDS JA4 FINGERPRINTING AND AGGREGATION ON JA3 AND JA4 FINGERPRINTS FOR RATE-BASED RULES

Summary from the TLDR InfoSec newsletter

A JA4 TLS client fingerprint contains a 36-character fingerprint of the TLS Client Hello which can be used for identifying known bad actors. JA4 fingerprints are now supported in match statements in AWS WAF. Additionally, AWS WAF has added support for both JA3 and JA4 fingerprints to rate-based rules.