In Waitress through version 1.4.0, if 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. Specially crafted requests containing special whitespace characters in the Transfer-Encoding header would 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. If 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. This issue is fixed in Waitress 1.4.1 through more strict HTTP field validation.
CVSS Details
- CVSS 3.1 Base Score: 7.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade py3-waitress | Mar 24, 2020 | Dec 26, 2019 |
| Debian | — | Upgrade waitress | Jan 3, 2020 | Dec 26, 2019 |
| Huawei Euleros 2_0_sp8 | — | Upgrade python2-waitress | Aug 31, 2020 | Dec 26, 2019 |
| Oracle Solaris | — | Upgrade library/python-2/waitress-26 to version 0.8.5-11.4.0.0.1.9.0 on Solaris 11.4Upgrade legacy/library/python/waitress-35 to version 1.4.3-11.4.21.0.1.69.0 on Solaris 11.4Upgrade library/python/waitress-35 to version 1.4.3-11.4.21.0.1.69.0 on Solaris 11.4Upgrade library/python/waitress-34 to version 1.4.3-11.4.21.0.1.69.0 on Solaris 11.4Upgrade library/python-2/waitress-27 to version 0.8.5-11.4.0.0.1.9.0 on Solaris 11.4Upgrade library/python-2/waitress to version 0.8.5-11.4.0.0.1.9.0 on Solaris 11.4Upgrade library/python/waitress to version 1.4.3-11.4.21.0.1.69.0 on Solaris 11.4Upgrade library/python/waitress-26 to version 0.8.5-11.4.0.0.1.9.0 on Solaris 11.4Upgrade library/python/waitress-27 to version 1.4.3-11.4.21.0.1.69.0 on Solaris 11.4Upgrade legacy/library/python/waitress-34 to version 1.4.3-11.4.21.0.1.69.0 on Solaris 11.4 | Jan 19, 2021 | Dec 26, 2019 |
| Suse | — | Upgrade python3-waitressUpgrade python2-waitress | Nov 12, 2020 | Dec 26, 2019 |
| Ubuntu | — | No solution exists | Jun 26, 2025 | Dec 26, 2019 |
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