Waitress up to 1.4.0 Proxy HTTP Request request smuggling

Summaryinfo

A vulnerability, which was classified as critical, was found in Waitress up to 1.4.0. This impacts an unknown function of the component Proxy Handler. Executing a manipulation as part of HTTP Request can lead to request smuggling. This vulnerability is tracked as CVE-2019-16789. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical was found in Waitress up to 1.4.0. This vulnerability affects some unknown functionality of the component Proxy Handler. The manipulation as part of a HTTP Request leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was disclosed 12/26/2019 (GitHub Repository). The advisory is shared for download at github.com. This vulnerability was named CVE-2019-16789 since 09/24/2019. The exploitation appears to be difficult. The attack can be initiated remotely. A single authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• Waitress

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4.0

License

• open-source

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Once again VulDB remains the best source for vulnerability data.

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