CVE-2019-16786
Description
Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: "Transfer-Encoding: gzip, chunked" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 1.4.1-1 |
| debian | bullseye | fixed | 1.4.1-1 |
| debian | forky | fixed | 1.4.1-1 |
| debian | sid | fixed | 1.4.1-1 |
| debian | trixie | fixed | 1.4.1-1 |
References
- https://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p
- https://nvd.nist.gov/vuln/detail/CVE-2019-16786
- https://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3
- https://access.redhat.com/errata/RHSA-2020:0720
- https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
- https://github.com/Pylons/waitress
- https://github.com/pypa/advisory-database/tree/main/vulns/waitress/PYSEC-2019-137.yaml
- https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.suse.com/security/cve/CVE-2019-16786.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/
- https://security-tracker.debian.org/tracker/CVE-2019-16786
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.