Scrapy leaks the authorization header on same-domain but cross-origin redirects

Impact

Since version 2.11.1, Scrapy drops the Authorization header when a request is redirected to a different domain. However, it keeps the header if the domain remains the same but the scheme (http/https) or the port change, all scenarios where the header should also be dropped.

In the context of a man-in-the-middle attack, this could be used to get access to the value of that Authorization header

Patches

Upgrade to Scrapy 2.11.2.

Workarounds

There is no easy workaround for unpatched versions of Scrapy. You can replace the built-in redirect middlewares with custom ones patched for this issue, but you have to patch them yourself, manually.

References

This security issue was reported and fixed by @szarny at https://huntr.com/bounties/27f6a021-a891-446a-ada5-0226d619dd1a/.