HTTP2: Apache httpd mod_http2 h2_session_process Denial of Service
This signature detects attempts to exploit a known vulnerability against Apache httpd module mod_http2. A successful attack can result in a denial-of-service condition.
Extended 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.
Affected Products
Apache http_server
References
CVE: CVE-2023-43622
Short Name
HTTP2:APACHE-MOD-HTTP2-DOS
Severity
Major
Recommended
True
Recommended Action
None
Category
HTTP2
Keywords
Apache CVE-2023-43622 Denial Service h2_session_process httpd mod_http2 of
Release Date
12/01/2023
Supported Platforms
srx-branch-19.3
vsrx3bsd-19.2
srx-19.4
vsrx3bsd-19.4
srx-branch-19.4
vsrx-19.4
vsrx-19.2
srx-19.3
Sigpack Version
3783
False Positive
Unknown
Vendors
Apache