[Security] Bump requests from 2.30.0 to 2.31.0

Bumps requests from 2.30.0 to 2.31.0. This update includes a security fix.

Vulnerabilities fixed

Unintended leak of Proxy-Authorization header in requests

Impact

Since Requests v2.3.0, Requests has been vulnerable to potentially leaking Proxy-Authorization headers to destination servers, specifically during redirects to an HTTPS origin. This is a product of how rebuild_proxies is used to recompute and reattach the Proxy-Authorization header to requests when redirected. Note this behavior has only been observed to affect proxied requests when credentials are supplied in the URL user information component (e.g. https://username:password@proxy:8080).

Current vulnerable behavior(s):

1. HTTP → HTTPS: leak
2. HTTPS → HTTP: no leak
3. HTTPS → HTTPS: leak
4. HTTP → HTTP: no leak

For HTTP connections sent through the proxy, the proxy will identify the header in the request itself and remove it prior to forwarding to the destination server. However when sent over HTTPS, the Proxy-Authorization header must be sent in the CONNECT request as the proxy has no visibility into further tunneled requests. This results in Requests forwarding the header to the destination server unintentionally, allowing a malicious actor to potentially exfiltrate those credentials.

The reason this currently works for HTTPS connections in Requests is the Proxy-Authorization header is also handled by urllib3 with our usage of the ProxyManager in adapters.py with proxy_manager_for. This will compute the required proxy headers in proxy_headers and pass them to the Proxy Manager, avoiding attaching them directly to the Request object. This will be our preferred option going forward for default usage.

Patches

Starting in Requests v2.31.0, Requests will no longer attach this header to redirects with an HTTPS destination. This should have no negative impacts on the default behavior of the library as the proxy credentials are already properly being handled by urllib3's ProxyManager.

For users with custom adapters, this may be potentially breaking if you were already working around this behavior. The previous functionality of rebuild_proxies doesn't make sense in any case, so we would encourage any users impacted to migrate any handling of Proxy-Authorization directly into their custom adapter.

... (truncated)

Patched versions: 2.31.0 Affected versions: >= 2.3.0, < 2.31.0

Release notes

Sourced from requests's releases.

v2.31.0

2.31.0 (2023-05-22)

Security

• Versions of Requests between v2.3.0 and v2.30.0 are vulnerable to potential forwarding of Proxy-Authorization headers to destination servers when following HTTPS redirects.

  When proxies are defined with user info (https://user:pass@proxy:8080), Requests will construct a Proxy-Authorization header that is attached to the request to authenticate with the proxy.

  In cases where Requests receives a redirect response, it previously reattached the Proxy-Authorization header incorrectly, resulting in the value being sent through the tunneled connection to the destination server. Users who rely on defining their proxy credentials in the URL are strongly encouraged to upgrade to Requests 2.31.0+ to prevent unintentional leakage and rotate their proxy credentials once the change has been fully deployed.

  Users who do not use a proxy or do not supply their proxy credentials through the user information portion of their proxy URL are not subject to this vulnerability.

  Full details can be read in our Github Security Advisory and CVE-2023-32681.

Changelog

Sourced from requests's changelog.

2.31.0 (2023-05-22)

Security

• Versions of Requests between v2.3.0 and v2.30.0 are vulnerable to potential forwarding of Proxy-Authorization headers to destination servers when following HTTPS redirects.

  When proxies are defined with user info (https://user:pass@proxy:8080), Requests will construct a Proxy-Authorization header that is attached to the request to authenticate with the proxy.

  In cases where Requests receives a redirect response, it previously reattached the Proxy-Authorization header incorrectly, resulting in the value being sent through the tunneled connection to the destination server. Users who rely on defining their proxy credentials in the URL are strongly encouraged to upgrade to Requests 2.31.0+ to prevent unintentional leakage and rotate their proxy credentials once the change has been fully deployed.

  Users who do not use a proxy or do not supply their proxy credentials through the user information portion of their proxy URL are not subject to this vulnerability.

  Full details can be read in our Github Security Advisory and CVE-2023-32681.

Commits

• 147c851 v2.31.0
• 74ea7cf Merge pull request from GHSA-j8r2-6x86-q33q
• 3022253 test on pypy 3.8 and pypy 3.9 on windows and macos (#6424)
• b639e66 test on py3.12 (#6448)
• d3d5044 Fixed a small typo (#6452)
• See full diff in compare view