CVE-2022-41556

Publication date 6 October 2022

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
lighttpd	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Ignored end of life, was needed
	22.10 kinetic	Fixed 1.4.65-2ubuntu1.1
	22.04 LTS jammy	Fixed 1.4.63-1ubuntu3.1
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Needs evaluation

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
lighttpd	Upstream: b18de6f

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	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-5903-1
lighttpd vulnerabilities
28 February 2023