Lab: Combining web cache poisoning vulnerabilities
Summary: PortSwigger's lab presents a web cache poisoning exercise that requires constructing a complex exploit chain, where a user visits the home page roughly once a minute with their language set to English. Solving it requires poisoning the cache with multiple malicious responses simultaneously and coordinating this with the victim's browsing behavior, including malicious JSON in a translation file with an XSS payload and a request to /?localized=1 carrying the lang cookie for Spanish.
Key Takeaway: The lab's premise is that a single poisoned cache entry can execute alert(document.cookie) in a visitor's browser, and the exploit only works when multiple malicious responses are aligned with when the victim actually browses - timing an attacker can observe and plan around.
Read the original at PortSwigger Research ↗
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