CVE-2023-43622

Severity
7.5HIGH
EPSS
61.3%
top 1.68%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedOct 23
Latest updateNov 22

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 upgr

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages4 packages

NVDapache/http_server2.4.552.4.58
Alpineapache2< 2.4.58-r0+8
Debianapache2< 2.4.59-1~deb11u1+3

🔴Vulnerability Details

5
OSV
apache2 vulnerabilities2023-11-22
CVEList
Apache HTTP Server: DoS in HTTP/2 with initial windows size 02023-10-23
OSV
CVE-2023-43622: 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 S2023-10-23
GHSA
GHSA-w2qc-22jv-44g8: 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 S2023-10-23
OSV
CVE-2023-43622: 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 S2023-10-23

📋Vendor Advisories

4
Ubuntu
Apache HTTP Server vulnerabilities2023-11-22
Red Hat
httpd: mod_http2: DoS in HTTP/2 with initial window size 02023-10-10
Microsoft
Apache HTTP Server: DoS in HTTP/2 with initial windows size 02023-10-10
Debian
CVE-2023-43622: apache2 - An attacker, opening a HTTP/2 connection with an initial window size of 0, was a...2023
CVE-2023-43622 (HIGH CVSS 7.5) | An attacker | cvebase.io