Collected research

Bypassing Web Cache Poisoning Countermeasures

James Kettle · PortSwigger · 5 October 2018

Examines why web cache poisoning defenses can fail when intermediaries and backends interpret headers differently. It also shows how cacheable block pages and incomplete validation can turn attempted fixes into persistent denial of service.

Record

Researcher

James Kettle

Published by

PortSwigger

Date

5 October 2018

Topic

HTTP

In the archive

• Collected in the 2018 research round

Tags

• cache-poisoning
• parser-differential
• waf-bypass
• dos
• mitigation
• owasp-a05-2021

This page is the archive's own catalogue record. The research is the work of James Kettle, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 16 September 2026.