cbcvebase.
CVE-2022-24761
published 2022-03-17

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…

PriorityP345high7.5CVSS 3.1
AVNACLPRNUINSUCNIHAN
EPSS
1.78%
75.8th percentile
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.

Affected

10 ranges
VendorProductVersion rangeFixed in
agendalesswaitress< 2.1.12.1.1
debiandebian_linux
debianwaitress< waitress 2.1.1-1 (bookworm)waitress 2.1.1-1 (bookworm)
msrcazl3_python-waitress_3.0.1-1_on_azure_linux_3.0
pylonswaitress< 2.1.12.1.1
pylonswaitress>= 0 < 1.4.4-1.1+deb11u11.4.4-1.1+deb11u1
pylonswaitress>= 0 < 2.1.1-12.1.1-1
pylonswaitress>= 0 < 2.1.1-12.1.1-1
pylonswaitress>= 0 < 2.1.1-12.1.1-1
pylonswaitress>= 0 < 2.1.12.1.1

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:P/A:N
osv7.5HIGH
vendor_debian7.5HIGH
vendor_msrc7.5HIGH
vendor_oracle7.5HIGH
vendor_redhat7.5HIGH
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.