CVE-2023-43622

23.10.2023, 07:15

An attacker, opening a HTTP/2 connection with an initial window size of 0, was able to block handling of that connection indefinitely in Apache HTTP Server. This could be used to exhaust worker resources in the server, similar to the well known "slow loris" attack pattern.
This has been fixed in version 2.4.58, so that such connection are terminated properly after the configured connection timeout.

This issue affects Apache HTTP Server: from 2.4.55 through 2.4.57.

Users are recommended to upgrade to version 2.4.58, which fixes the issue.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
apache	CNA	---				---
CVE	ADP	---				---
CISA-ADP	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 98%

Vendor	Product	Version
apache	http_server	2.4.55 ≤ 𝑥 < 2.4.58

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

apache2

bullseye	2.4.62-1~deb11u1 fixed
buster	not-affected
bullseye (security)	2.4.62-1~deb11u2 fixed
bookworm	2.4.62-1~deb12u2 fixed
bookworm (security)	2.4.62-1~deb12u2 fixed
sid	2.4.62-3 fixed
trixie	2.4.62-3 fixed

Ubuntu Releases

Ubuntu Product

Codename

apache2

mantic	Fixed 2.4.57-2ubuntu2.1 released
lunar	Fixed 2.4.55-1ubuntu2.1 released
jammy	not-affected
focal	not-affected
bionic	not-affected
xenial	not-affected
trusty	not-affected

Common Weakness Enumeration

CWE-400 - Uncontrolled Resource Consumption
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

References

https://httpd.apache.org/security/vulnerabilities_24.html

https://security.netapp.com/advisory/ntap-20231027-0011/

https://httpd.apache.org/security/vulnerabilities_24.html

https://security.netapp.com/advisory/ntap-20231027-0011/