CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
AI Score
Confidence
Low
EPSS
Percentile
10.3%
Express.js minimalist web framework for node. Versions of Express.js prior to 4.19.0 and all pre-release alpha and beta versions of 5.0 are affected by an open redirect vulnerability using malformed URLs. When a user of Express performs a redirect using a user-provided URL Express performs an encode using encodeurl
on the contents before passing it to the location
header. This can cause malformed URLs to be evaluated in unexpected ways by common redirect allow list implementations in Express applications, leading to an Open Redirect via bypass of a properly implemented allow list. The main method impacted is res.location()
but this is also called from within res.redirect()
. The vulnerability is fixed in 4.19.2 and 5.0.0-beta.3.
expressjs.com/en/4x/api.html#res.location
github.com/expressjs/express/commit/0867302ddbde0e9463d0564fea5861feb708c2dd
github.com/expressjs/express/commit/0b746953c4bd8e377123527db11f9cd866e39f94
github.com/expressjs/express/pull/5539
github.com/expressjs/express/security/advisories/GHSA-rv95-896h-c2vc
github.com/koajs/koa/issues/1800