CVE Vulnerability

CVE-2022-24761

Waitress is a Web Server Gateway Interface server for Python 2 and 3. When using Waitress versions 2.1.0 and prior behind a proxy that does not properly validate the incoming HTTP request matches the RFC7230 standard, Waitress and the frontend proxy may disagree on where one request starts and where it ends. This would allow requests to be smuggled via the front-end proxy to waitress and later behavior. There are two classes of vulnerability that may lead to request smuggling that are addressed by this advisory: The use of Python's `int()` to parse strings into integers, leading to `+10` to be parsed as `10`, or `0x01` to be parsed as `1`, where as the standard specifies that the string should contain only digits or hex digits; and Waitress does not support chunk extensions, however it was discarding them without validating that they did not contain illegal characters. This vulnerability has been patched in Waitress 2.1.1. A workaround is available. When deploying a proxy in front of waitress, turning on any and all functionality to make sure that the request matches the RFC7230 standard. Certain proxy servers may not have this functionality though and users are encouraged to upgrade to the latest version of waitress instead.

5 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 2.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

Scope

7.5 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References
Link Resource
https://github.com/Pylons/waitress/commit/9e0b8c801e4d505c2ffc91b891af4ba48af715e0 Patch Release Notes
https://github.com/Pylons/waitress/security/advisories/GHSA-4f7p-27jc-3c36 Third Party Advisory
https://github.com/Pylons/waitress/releases/tag/v2.1.1 Release Notes Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html Mailing List Third Party Advisory
https://www.debian.org/security/2022/dsa-5138 Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:agendaless:waitress:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
Information

Published : 2022-03-17 01:15

Updated : 2022-09-23 06:57

NVD link : CVE-2022-24761

Mitre link : CVE-2022-24761

Products Affected
No products.
CWE
CWE-444

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