CVE-2022-24761

Publication date 17 March 2022

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
waitress 22.04 LTS jammy
Fixed 1.4.4-1.1ubuntu1
21.10 impish
Fixed 1.4.4-1.1ubuntu0.1
20.04 LTS focal
Fixed 1.4.1-1ubuntu0.1
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Ignored end of standard support

Notes

leosilva

there is no support for rfc7230 on bionic and old releases.

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N