FoxIO discloses QPACK flaws letting one HTTP/3 connection crash servers via up to 4,000x memory amplification
FoxIO disclosed a class of denial-of-service flaws in the QPACK header compression used by HTTP/3. It affects seven of the ten stacks the firm tested and was released with working proof-of-concept code. An unauthenticated remote attacker can send a small compressed header batch that expands in memory by thousands of times, exhausting a de…