Impact
Authorization and Cookie headers on requests are sensitive information. On making a request which responds with a redirect to a URI with a different port, if we choose to follow it, we should remove the Authorization and Cookie headers from the request, before containing. Previously, we would only consider a change in host or scheme downgrade. Now, we consider any change in host, port or scheme to be a change in origin.
Patches
Affected Guzzle 7 users should upgrade to Guzzle 7.4.5 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.8 or 7.4.5.
Workarounds
An alternative approach would be to use your own redirect middleware, rather than ours, if you are unable to upgrade. If you do not require or expect redirects to be followed, one should simply disable redirects all together.
References
For more information
If you have any questions or comments about this advisory, please get in touch with us in #guzzle on the PHP HTTP Slack. Do not report additional security advisories in that public channel, however – please follow our vulnerability reporting process.