When a Mongodb used 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().
var lowerLoc = loc.toLowerCase();
var encodedUrl = encodeUrl(loc);
if (lowerLoc.indexOf('https://') === 0 || lowerLoc.indexOf('http://') === 0) {
try {
var parsedUrl = urlParse(loc);
var parsedEncodedUrl = urlParse(encodedUrl);
// Because this can encode the host, check that we did not change the host
if (parsedUrl.host !== parsedEncodedUrl.host) {
// If the host changes after encodeUrl, return the original url
return this.set('Location', loc);
}
} catch (e) {
// If parse fails, return the original url
return this.set('Location', loc);
}
}
Impact
When a Mongodb used Express performs a redirect using a user-provided URL Express performs an encode using encodeurl on the contents before passing it to the
locationheader. 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 isres.location()but this is also called from withinres.redirect().CVE-2024-29041 CWE-601 CWE-1286
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NJira: requested to mongodb team for created the Jira Ticket
Changes
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Notes
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