Improved fix for open redirect allow list bypass

Co-authored-by: Jon Church <me@jonchurch.com>
Co-authored-by: Blake Embrey <hello@blakeembrey.com>
This commit is contained in:
Wes Todd
2024-03-21 12:13:56 -05:00
parent 4f0f6cc67d
commit 0b746953c4
3 changed files with 280 additions and 63 deletions

View File

@@ -34,7 +34,6 @@ var extname = path.extname;
var mime = send.mime;
var resolve = path.resolve;
var vary = require('vary');
var urlParse = require('url').parse;
/**
* Response prototype.
@@ -56,6 +55,7 @@ module.exports = res
*/
var charsetRegExp = /;\s*charset\s*=/;
var schemaAndHostRegExp = /^(?:[a-zA-Z][a-zA-Z0-9+.-]*:)?\/\/[^\\\/\?]+/;
/**
* Set status `code`.
@@ -905,32 +905,23 @@ res.cookie = function (name, value, options) {
*/
res.location = function location(url) {
var loc = String(url);
var loc;
// "back" is an alias for the referrer
if (url === 'back') {
loc = this.req.get('Referrer') || '/';
} else {
loc = String(url);
}
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);
}
}
var m = schemaAndHostRegExp.exec(loc);
var pos = m ? m[0].length + 1 : 0;
// set location
return this.set('Location', encodedUrl);
// Only encode after host to avoid invalid encoding which can introduce
// vulnerabilities (e.g. `\\` to `%5C`).
loc = loc.slice(0, pos) + encodeUrl(loc.slice(pos));
return this.set('Location', loc);
};
/**