Version Details and Security Vulnerabilities

fast-redact is a package that provides do very fast object redaction. A Prototype Pollution vulnerability in the nestedRestore function of fast-redact version 3.5.0 and before allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.

Impact

passing untrusted user input - even after sanitizing it - to SendStream.redirect() may execute untrusted code

Patches

this issue is patched in send 0.19.0

Workarounds

users 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 allowlist

Details

successful exploitation of this vector requires the following:

1. The attacker MUST control the input to response.redirect()
2. express MUST NOT redirect before the template appears
3. the browser MUST NOT complete redirection before:
4. the user MUST click on the link in the template