Detections
Analytics
CVE-2019-16786
high
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.
References
https://www.oracle.com/security-alerts/cpuapr2022.html
https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html
https://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p
https://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3
https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes