{"answers":{"affected":"2 open source packages ship an affected version, including waitress.","exploited":"There is no known exploitation of GHSA-m5ff-3wj3-8ph4 in the wild and no public exploit code.","fix":"Upgrade waitress to 1.4.1 or later.","what":"GHSA-m5ff-3wj3-8ph4 is a vulnerability in waitress, published on 26 Dec 2019. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for GHSA-m5ff-3wj3-8ph4 and fix it if it is affected.\n\nWhat it is: GHSA-m5ff-3wj3-8ph4 is a vulnerability in waitress, published on 26 Dec 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of GHSA-m5ff-3wj3-8ph4 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- waitress (PyPI): affected all versions; fixed in 1.4.1\n- waitress (PyPI): affected all versions; fixed in 1.4.1\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/GHSA-m5ff-3wj3-8ph4/ (Markdown: https://insights.sbomify.com/GHSA-m5ff-3wj3-8ph4/index.md)","id":"GHSA-m5ff-3wj3-8ph4","markdown":"https://insights.sbomify.com/GHSA-m5ff-3wj3-8ph4/index.md","name":"GHSA-m5ff-3wj3-8ph4","record":{"aliases":[],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Python WSGI server","requires_auth":"none","summary":"Attackers can smuggle HTTP requests via invalid whitespace in headers when Waitress is behind a proxy, potentially causing cache poisoning or information disclosure.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"### Impact\n\nIf a proxy server is used in front of waitress, an invalid request may be sent by an attacker that bypasses the front-end and is parsed differently by waitress leading to a potential for HTTP request smuggling.\n\n```\nContent-Length: 10\nTransfer-Encoding: [\\x0b]chunked\n```\n\nFor clarity:\n\n```\n0x0b == vertical tab\n```\n\nWould get parsed by Waitress as being a `chunked` request, but a front-end server would use the `Content-Length` instead as the `Transfer-Encoding` header is considered invalid due to containing invalid characters.\n\nIf a front-end server does HTTP pipelining to a backend Waitress server this could lead to HTTP request splitting which may lead to potential cache poisoning or unexpected information disclosure.\n\n### Patches\n\nPlease upgrade to Waitress 1.4.1 which fixes this issue with stricter HTTP field validation.\n\nWaitress 1.4.1 due to this change has become much more strict in what is allowed in header values, while the maintainers don't believe that these changes will cause any issues, it may cause failures with non-conformist reverse proxies or clients, and it is highly recommend that users validate the changes in their environment and make sure it won't cause any unacceptable failures.\n\n### Workarounds\n\nYou may enable additional protections on front-end servers, those that follow RFC7230 correctly would drop the request with a 400 Bad Request.\n\nWaitress will now correctly responds to the request with a 400 Bad Request, and will drop the connection to avoid any potential HTTP pipelining issues.\n\n### References\n\nThis was mentioned in https://portswigger.net/research/http-desync-attacks-what-happened-next and was specifically mentioned as being an issue in HAProxy which did not properly filter it in this article: https://nathandavison.com/blog/haproxy-http-request-smuggling\n\n### Thanks\n\nThe Pylons Project would like to thank ZeddYu Lu for doing extended testing against Waitress 1.4.0 and bringing this to our attention!\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* open an issue at https://github.com/Pylons/waitress/issues (if not sensitive or security related)\n* email the Pylons Security mailing list: pylons-project-security@googlegroups.com (if security related)","ecosystems":["PyPI"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":true,"headline":"HTTP Request Smuggling: Invalid whitespace characters in headers in Waitress","id":"GHSA-m5ff-3wj3-8ph4","indexable":true,"kev":null,"kind":"advisory","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"other","year":"2019"},"n_packages":2,"n_references":null,"packages":[{"ecosystem":"PyPI","fixed":["1.4.1"],"introduced":["0"],"last_affected":[],"package":"waitress","purl":null,"source":"GHSA-m5ff-3wj3-8ph4"},{"ecosystem":"PyPI","fixed":["1.4.1"],"introduced":["0"],"last_affected":[],"package":"waitress","purl":"pkg:pypi/waitress","source":"GHSA-m5ff-3wj3-8ph4"}],"products":null,"published":"2019-12-26","related":[],"sources":[{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":"Attackers can smuggle HTTP requests via invalid whitespace in headers when Waitress is behind a proxy, potentially causing cache poisoning or information disclosure.","url":"https://insights.sbomify.com/GHSA-m5ff-3wj3-8ph4/"}