GHSA-jm3v-qxmh-hxwv Scrapy's redirects ignoring scheme-specific proxy settings
Scrapy fails to switch proxy settings during HTTP/HTTPS redirects, potentially exposing traffic to unintended proxies if scheme-specific proxies are configured.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-jm3v-qxmh-hxwv?
GHSA-jm3v-qxmh-hxwv is a vulnerability in Scrapy, published on 14 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Impact
When using system proxy settings, which are scheme-specific (i.e. specific to http:// or https:// URLs), Scrapy was not accounting for scheme changes during redirects.
For example, an HTTP request would use the proxy configured for HTTP and, when redirected to an HTTPS URL, the new HTTPS request would still use the proxy configured for HTTP instead of switching to the proxy configured for HTTPS. Same the other way around.
If you have different proxy configurations for HTTP and HTTPS in your system for security reasons (e.g., maybe you don’t want one of your proxy providers to be aware of the URLs that you visit with the other one), this would be a security issue.
Patches
Upgrade to Scrapy 2.11.2.
Workarounds
Replace the built-in retry middlewares (RedirectMiddleware and MetaRefreshMiddleware) and the HttpProxyMiddleware middleware with custom ones that implement the fix from Scrapy 2.11.2, and verify that they work as intended.
References
This security issue was reported by @redapple at https://github.com/scrapy/scrapy/issues/767.
Which versions are affected by GHSA-jm3v-qxmh-hxwv?
2 open source packages ship an affected version, including Scrapy and scrapy.
| Package | Affected | Fixed in |
|---|---|---|
Scrapy PyPI | All versions | 2.11.2 |
scrapy PyPI | All versions | 2.11.2 |
How do I fix GHSA-jm3v-qxmh-hxwv?
Upgrade Scrapy to 2.11.2 or later.
Is GHSA-jm3v-qxmh-hxwv being exploited?
There is no known exploitation of GHSA-jm3v-qxmh-hxwv in the wild and no public exploit code.