CVE-2023-43622
Publication date 23 October 2023
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
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.
Read the notes from the security team
Why is this CVE low priority?
Apache developers consider this to be a low-impact issue
Status
Package | Ubuntu Release | Status |
---|---|---|
apache2 | ||
22.04 LTS jammy |
Not affected
|
|
20.04 LTS focal |
Not affected
|
|
18.04 LTS bionic |
Not affected
|
|
16.04 LTS xenial |
Not affected
|
|
14.04 LTS trusty |
Not affected
|
Notes
mdeslaur
backporting this to jammy and earlier will likely require backporting the whole 2.0.10 version of the http/2 module as it refactors how connections and streams are handled: https://github.com/apache/httpd/commit/9767274b884a110e9244f59f50bd31ff1cae2933
Severity score breakdown
Parameter | Value |
---|---|
Base score | 7.5 · High |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | None |
Scope | Unchanged |
Confidentiality | None |
Integrity impact | None |
Availability impact | High |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References
Related Ubuntu Security Notices (USN)
- USN-6506-1
- Apache HTTP Server vulnerabilities
- 22 November 2023