express vulnerable to XSS via response.redirect()
ImpactIn express <4.20.0, passing untrusted user input - even after sanitizing it - to `response.redirect()` may execute untrusted codePatchesthis issue is patched in express 4.20.0Workaroundsusers are encouraged to upgrade to the patched version of express, but otherwise can workaround this issue by making sure any untrusted inputs are safe, ideally by validating them against an explicit allowlistDetailssuccessful exploitation of this vector requires the following:The attacker MUST control the input to response.redirect()express MUST NOT redirect before the template appearsthe browser MUST NOT complete redirection before:the user MUST click on the link in the template