Web Hack List

Collected research

Bypassing CSP with policy injection

A URL parameter reflected into a CSP report-uri directive lets an attacker append directives to the policy. On Edge a semicolon and underscore make the syntax invalid so the whole policy is dropped, and on Chrome an appended script-src-elem directive overrides the existing script-src, in both cases restoring script execution and turning a blocked injection into working XSS.

Record

Researcher
Gareth Heyes
Published by
PortSwigger Research
Date
Topic
XSS

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