Bugzilla – Bug 1216423
VUL-0: CVE-2023-45802: apache2: HTTP/2 stream memory not reclaimed right away on RST
Last modified: 2024-07-18 17:45:05 UTC
Severity: moderate Affected versions: - Apache HTTP Server 2.4.17 through 2.4.57 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. Credit: Will Dormann of Vul Labs (finder) David Warren of Vul Labs (finder) References: https://httpd.apache.org/security/vulnerabilities_24.html https://httpd.apache.org/ https://www.cve.org/CVERecord?id=CVE-2023-45802 Timeline: 2023-10-12: reported
Oh, I see my mistake now, I thought this was just the RST CVE, which apache2 is not impacted as it is. Instead it's a side-effect of that one (discovered later) because a possible DDoS via memory exhaustion can be performed... and I thought this was only affecting it because while using mod_http2 (which was fixed at the time). I had everything mixed up in my head. I'm reopening this issue and assigning it back to me. Also, already working on the fix: * https://github.com/apache/httpd/commit/8943c469eb6e60726cc4f73e3d787173c059c5ef Thanks for the review Marcus, you are on point, as always. Once fixed I'll send it back to sec for review again.