HTTP Request Smuggling Affecting waitress package, versions [,1.4.0)
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Test your applications- Snyk ID SNYK-PYTHON-WAITRESS-538575
- published 21 Dec 2019
- disclosed 13 Dec 2019
- credit Unknown
Introduced: 13 Dec 2019
CVE-2019-16786 Open this link in a new tabHow to fix?
Upgrade waitress to version 1.4.0 or higher.
Overview
waitress is a production-quality pure-Python WSGI server with very acceptable performance.
Affected versions of this package are vulnerable to HTTP Request Smuggling. It 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.