Impact
Previous version of Guzzle contain a vulnerability with the cookie middleware. The vulnerability is that it is not checked if the cookie domain equals the domain of the server which sets the cookie via the Set-Cookie header, allowing a malicious server to set cookies for unrelated domains. For example an attacker at www.example.com might set a session cookie for api.example.net, logging the Guzzle client into their account and retrieving private API requests from the security log of their account.
Note that our cookie middleware is disabled by default, so most library consumers will not be affected by this issue. Only those who manually add the cookie middleware to the handler stack or construct the client with ['cookies' => true] are affected. Moreover, those who do not use the same Guzzle client to call multiple domains and have disabled redirect forwarding are not affected by this vulnerability.
Patches
Affected Guzzle 7 users should upgrade to Guzzle 7.4.3 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.6 or 7.4.3.
Workarounds
If you do not need support for cookies, turn off the cookie middleware. It is already off by default, but if you have turned it on and no longer need it, turn it off.
References
RFC6265 Section 5.3 RFC9110 Section 15.4
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.
Change in port should be considered a change in origin
Impact
Authorization headers on requests are sensitive information. When using our Curl handler, it is possible to use the CURLOPTHTTPAUTH option to specify an Authorization header. On making a request which responds with a redirect to a URI with a different origin, if we choose to follow it, we should remove the CURLOPTHTTPAUTH and CURLOPTUSERPWD options before continuing, stopping curl from appending the Authorization header to the new request. Previously, we would only consider a change in host. 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. Note that a partial fix was implemented in Guzzle 7.4.2, where a change in host would trigger removal of the curl-added Authorization header, however this earlier fix did not cover change in scheme or change in port.
Workarounds
If you do not require or expect redirects to be followed, one should simply disable redirects all together. Alternatively, one can specify to use the Guzzle stream handler backend, rather than curl.
References
RFC9110 Section 15.4 CVE-2022-27776
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.
Impact
Cookie headers on requests are sensitive information. On making a request using the https scheme to a server which responds with a redirect to a URI with the http scheme, or on making a request to a server which responds with a redirect to a a URI to a different host, we should not forward the Cookie header on. Prior to this fix, only cookies that were managed by our cookie middleware would be safely removed, and any Cookie header manually added to the initial request would not be stripped. We now always strip it, and allow the cookie middleware to re-add any cookies that it deems should be there.
Patches
Affected Guzzle 7 users should upgrade to Guzzle 7.4.4 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.7 or 7.4.4.
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
RFC9110 Section 15.4
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.
Impact
Authorization headers on requests are sensitive information. On making a request using the https scheme to a server which responds with a redirect to a URI with the http scheme, we should not forward the Authorization header on. This is much the same as to how we don't forward on the header if the host changes. Prior to this fix, https to http downgrades did not result in the Authorization header being removed, only changes to the host.
Patches
Affected Guzzle 7 users should upgrade to Guzzle 7.4.4 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.7 or 7.4.4.
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
RFC9110 Section 15.4
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.