Vulnerability CVE-2019-16789


Published: 2019-12-26

Description:
In Waitress through version 1.4.0, if a proxy server is used in front of waitress, an invalid request may be sent by an attacker that bypasses the front-end and is parsed differently by waitress leading to a potential for HTTP request smuggling. Specially crafted requests containing special whitespace characters in the Transfer-Encoding header would get parsed by Waitress as being a chunked request, but a front-end server would use the Content-Length instead as the Transfer-Encoding header is considered invalid due to containing invalid characters. If a front-end server does HTTP pipelining to a backend Waitress server this could lead to HTTP request splitting which may lead to potential cache poisoning or unexpected information disclosure. This issue is fixed in Waitress 1.4.1 through more strict HTTP field validation.

Type:

CWE-444

(Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling'))

CVSS2 => (AV:N/AC:L/Au:N/C:P/I:P/A:N)

CVSS Base Score
Impact Subscore
Exploitability Subscore
6.4/10
4.9/10
10/10
Exploit range
Attack complexity
Authentication
Remote
Low
No required
Confidentiality impact
Integrity impact
Availability impact
Partial
Partial
None
Affected software
Agendaless -> Waitress 

 References:
https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
https://github.com/github/advisory-review/pull/14604
https://github.com/Pylons/waitress/commit/11d9e138125ad46e951027184b13242a3c1de017

Copyright 2022, cxsecurity.com

 

Back to Top