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.
Created python-waitress tracking bugs for this issue:
Affects: epel-all [bug 1791417]
Affects: fedora-all [bug 1791416]
Affects: openstack-rdo [bug 1791418]
While Red Hat Quay declares a dependency on python-waitress, it doesn't appear to be used in the code. Setting the impact to low for Red Hat Quay. It may be fixed in a future version.
All affected Red Hat products ship but do not use the flawed version of python-waitress. The impact for these products is therefore rated as having a security impact of Low.