ReferenceGlossary
ReDoS (regular expression denial of service)
A denial of service where a crafted input makes a backtracking regular expression engine take exponential or very long time. One bad pattern can pin a CPU core per request.
Security
In Quorum#
The Regex backtracking Incident can start from Series B when you run a WAF. A new WAF rule backtracks on long inputs, and every WAF keeps only 10% of its capacity, so traffic through it fails or queues. Press Disable rule on the WAF to end it at once. In real systems, a canary rollout of rules catches this before it reaches every server.
Read next#
WAF (web application firewall), Canary deployment, Blast radius