cve/2019/CVE-2019-16786.md

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.

POC

Reference

• https://www.oracle.com/security-alerts/cpuapr2022.html
• https://www.oracle.com/security-alerts/cpuapr2022.html

Github

• https://github.com/Live-Hack-CVE/CVE-2019-16786