CVE-2023-43622
Fixed in a distro release EPSS 69%
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.
Products: Apache Software Foundation Apache HTTP Server
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux 9 | mod_http2 | 2.0.26-1.el9 |
| Alpine 3.15 | apache2 | 2.4.58-r0 |
| Alpine 3.16 | apache2 | 2.4.58-r0 |
| Alpine 3.17 | apache2 | 2.4.58-r0 |
| Alpine 3.18 | apache2 | 2.4.58-r0 |
| Alpine 3.19 | apache2 | 2.4.58-r0 |
| Alpine 3.20 | apache2 | 2.4.58-r0 |
| Alpine 3.21 | apache2 | 2.4.58-r0 |
| Alpine 3.22 | apache2 | 2.4.58-r0 |
| Alpine 3.23 | apache2 | 2.4.58-r0 |
| Alpine 3.24 | apache2 | 2.4.58-r0 |
| Debian 11 | apache2 | 2.4.59-1~deb11u1 |
| Debian 12 | apache2 | 2.4.59-1~deb12u1 |
| Debian 13 | apache2 | 2.4.58-1 |
| Debian 14 | apache2 | 2.4.58-1 |
| Red Hat Enterprise Linux 9 | mod_http2 | 0:2.0.26-1.el9 |
| Red Hat Enterprise Linux 9 | mod_http2-debuginfo | 0:2.0.26-1.el9 |
| Red Hat Enterprise Linux 9 | mod_http2-debugsource | 0:2.0.26-1.el9 |
| Ubuntu 20.04 LTS | apache2 | 2.4.41-4ubuntu3.14 |
| Ubuntu 20.04 LTS | apache2 | 2.4.41-4ubuntu3.15 |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.6 |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.7 |
| openSUSE Tumbleweed | apache2 | 2.4.58-1.1 |