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.

CVSS Metrics

• v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 59.54%• Percentile: 98%

Techniques & Countermeasures

• CWE-400•Uncontrolled Resource Consumption

  The product does not properly control the allocation and maintenance of a limited resource.

Affected Systems

• apache software foundation•apache http server

  ≥ 2.4.55, ≤ 2.4.57

• Unknown•HTTP Server

  ≥ 2.4.55, < 2.4.58

References (2)

• https://httpd.apache.org/security/vulnerabilities_24.html
• https://security.netapp.com/advisory/ntap-20231027-0011/