Package Instance

Scrapy decompression bomb vulnerability
### Impact

Scrapy limits allowed response sizes by default through the [`DOWNLOAD_MAXSIZE`](https://docs.scrapy.org/en/latest/topics/settings.html#download-maxsize) and [`DOWNLOAD_WARNSIZE`](https://docs.scrapy.org/en/latest/topics/settings.html#download-warnsize) settings.

However, those limits were only being enforced during the download of the raw, usually-compressed response bodies, and not during decompression, making Scrapy vulnerable to [decompression bombs](https://cwe.mitre.org/data/definitions/409.html).

A malicious website being scraped could send a small response that, on decompression, could exhaust the memory available to the Scrapy process, potentially affecting any other process sharing that memory, and affecting disk usage in case of uncompressed response caching.

### Patches

Upgrade to Scrapy 2.11.1.

If you are using Scrapy 1.8 or a lower version, and upgrading to Scrapy 2.11.1 is not an option, you may upgrade to Scrapy 1.8.4 instead.

### Workarounds

There is no easy workaround.

Disabling HTTP decompression altogether is impractical, as HTTP compression is a rather common practice.

However, it is technically possible to manually backport the 2.11.1 or 1.8.4 fix, replacing the corresponding components of an unpatched version of Scrapy with patched versions copied into your own code.

### Acknowledgements

This security issue was reported by @dmandefy  [through huntr.com](https://huntr.com/bounties/c4a0fac9-0c5a-4718-9ee4-2d06d58adabb/).

Scrapy authorization header leakage on cross-domain redirect
### Impact

When you send a request with the `Authorization` header to one domain, and the response asks to redirect to a different domain, Scrapy’s built-in redirect middleware creates a follow-up redirect request that keeps the original `Authorization` header, leaking its content to that second domain.

The [right behavior](https://fetch.spec.whatwg.org/#ref-for-cors-non-wildcard-request-header-name) would be to drop the `Authorization` header instead, in this scenario.

### Patches

Upgrade to Scrapy 2.11.1.

If you are using Scrapy 1.8 or a lower version, and upgrading to Scrapy 2.11.1 is not an option, you may upgrade to Scrapy 1.8.4 instead.

### Workarounds

If you cannot upgrade, make sure that you are not using the `Authentication` header, either directly or through some third-party plugin.

If you need to use that header in some requests, add `"dont_redirect": True` to the `request.meta` dictionary of those requests to disable following redirects for them.

If you need to keep (same domain) redirect support on those requests, make sure you trust the target website not to redirect your requests to a different domain.

### Acknowledgements

This security issue was reported by @ranjit-git  [through huntr.com](https://huntr.com/bounties/49974321-2718-43e3-a152-62b16eed72a9/).