{"id":"GHSA-9x8m-2xpf-crp3","aliases":[],"url":"https://o3.security/vulnerability/GHSA-9x8m-2xpf-crp3","summary":"Scrapy before 2.6.2 and 1.8.3 vulnerable to one proxy sending credentials to another","details":"### Impact\n\nWhen the [built-in HTTP proxy downloader middleware](https://docs.scrapy.org/en/2.6/topics/downloader-middleware.html#module-scrapy.downloadermiddlewares.httpproxy) processes a request with `proxy` metadata, and that `proxy` metadata includes proxy credentials, the built-in HTTP proxy downloader middleware sets the `Proxy-Authentication` header, but only if that header is not already set.\n\nThere are third-party proxy-rotation downloader middlewares that set different `proxy` metadata every time they process a request.\n\nBecause of request retries and redirects, the same request can be processed by downloader middlewares more than once, including both the built-in HTTP proxy downloader middleware and any third-party proxy-rotation downloader middleware.\n\nThese third-party proxy-rotation downloader middlewares could change the `proxy` metadata of a request to a new value, but fail to remove the `Proxy-Authentication` header from the previous value of the `proxy` metadata, causing the credentials of one proxy to be leaked to a different proxy.\n\nIf you rotate proxies from different proxy providers, and any of those proxies requires credentials, you are affected, unless you are handling proxy rotation as described under **Workarounds** below. If you use a third-party downloader middleware for proxy rotation, the same applies to that downloader middleware, and installing a patched version of Scrapy may not be enough; patching that downloader middlware may be necessary as well.\n\n### Patches\n\nUpgrade to Scrapy 2.6.2.\n\nIf you are using Scrapy 1.8 or a lower version, and upgrading to Scrapy 2.6.2 is not an option, you may upgrade to Scrapy 1.8.3 instead.\n\n### Workarounds\n\nIf you cannot upgrade, make sure that any code that changes the value of the `proxy` request meta also removes the `Proxy-Authorization` header from the request if present.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* [Open an issue](https://github.com/scrapy/scrapy/issues)\n* [Email us](mailto:opensource@zyte.com)\n","published":"2022-07-29T22:26:57Z","modified":"2024-11-28T05:41:04.660880Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"scrapy","fixedVersion":"1.8.3"},{"ecosystem":"PyPI","name":"scrapy","fixedVersion":"2.6.2"}],"fix":{"url":"https://github.com/scrapy/scrapy/commit/af7dd16d8ded3e6cb2946603688f4f4a5212e80f","label":"scrapy/scrapy@af7dd16"},"references":[{"type":"WEB","url":"https://github.com/scrapy/scrapy/security/advisories/GHSA-9x8m-2xpf-crp3"},{"type":"WEB","url":"https://github.com/scrapy/scrapy/commit/af7dd16d8ded3e6cb2946603688f4f4a5212e80f"},{"type":"PACKAGE","url":"https://github.com/scrapy/scrapy"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2024-11-28T05:41:04.660880Z"}}