What’s Vulnerable › Vulnerabilities
CVE-2023-45802: Apache HTTP Server: HTTP/2 stream memory not reclaimed right away on RST
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 3.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2023-10-23 · updated 2026-06-17
- Weakness: CWE-404
Description
When a HTTP/2 stream was reset (RST frame) by a client, there was a time window were the request's memory resources were not reclaimed immediately. Instead, de-allocation was deferred to connection close. A client could send new requests and resets, keeping the connection busy and open and causing the memory footprint to keep on growing. On connection close, all resources were reclaimed, but the process might run out of memory before that. This was found by the reporter during testing of CVE-2023-44487 (HTTP/2 Rapid Reset Exploit) with their own test client. During "normal" HTTP/2 use, the probability to hit this bug is very low. The kept memory would not become noticeable before the connection closes or times out. Users are recommended to upgrade to version 2.4.58, which fixes the issue.
Affected products
- Apache HTTP Server: from 2.4.17 before 2.4.58 — fixed in 2.4.58
- Debian Linux: 10.0
- Fedoraproject Fedora: 37, 38, 39
How to fix
Upgrade to a fixed version: Apache HTTP Server 2.4.58. Check the vendor advisory for mitigations.
References
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://lists.debian.org/debian-lts-announce/2024/05/msg00013.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2MBEPPC36UBVOZZNAXFHKLFGSLCMN5LI/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BFQD3KUEMFBHPAPBGLWQC34L4OWL5HAZ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WE2I52RHNNU42PX6NZ2RBUHSFFJ2LVZX/
- https://security.netapp.com/advisory/ntap-20231027-0011/
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