Fix CVE–2024–29041

[debricked]

CVE–2024–29041

Vulnerability details

Description

Improper Validation of Syntactic Correctness of Input

The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax.

NVD

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.

GitHub

Express.js Open Redirect in malformed URLs

Impact

Versions of Express.js prior to 4.19.2 and pre-release alpha and beta versions before 5.0.0-beta.3 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().

Patches

expressjs/express@0867302
expressjs/express@0b74695

An initial fix went out with [email protected], we then patched a feature regression in 4.19.1 and added improved handling for the bypass in 4.19.2.

Workarounds

The fix for this involves pre-parsing the url string with either require('node:url').parse or new URL. These are steps you can take on your own before passing the user input string to res.location or res.redirect.

References

expressjs/express#5539
koajs/koa#1800
https://expressjs.com/en/4x/api.html#res.location

CVSS details - 6.1

 

CVSS3 metrics
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User interaction	Required
Scope	Changed
Confidentiality	Low
Integrity	Low
Availability	None

References

    NVD - CVE-2024-29041
    Express.js Open Redirect in malformed URLs · CVE-2024-29041 · GitHub Advisory Database · GitHub
    THIRD PARTY
    THIRD PARTY
    Express 4.x - API Reference
    THIRD PARTY
    THIRD PARTY
    THIRD PARTY

 

Related information

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