CVE-2023-43622

Name	CVE-2023-43622
Description	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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-5662-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
apache2 (PTS)	buster	2.4.38-3+deb10u8	fixed
	buster (security)	2.4.38-3+deb10u10	fixed
	bullseye	2.4.56-1~deb11u2	vulnerable
	bullseye (security)	2.4.59-1~deb11u1	fixed
	bookworm	2.4.57-2	vulnerable
	bookworm (security)	2.4.59-1~deb12u1	fixed
	trixie	2.4.58-1	fixed
	sid	2.4.59-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin
apache2	source	buster	(not affected)
apache2	source	bullseye	2.4.59-1~deb11u1	DSA-5662-1
apache2	source	bookworm	2.4.59-1~deb12u1	DSA-5662-1
apache2	source	(unstable)	2.4.58-1

Notes

[buster] - apache2 <not-affected> (Vulnerable code introduced later)
https://www.openwall.com/lists/oss-security/2023/10/19/5
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2023-43622