CVE-2023-45802 Apache HTTP Server: HTTP/2 stream memory not reclaimed right away on RST

2023-10-2306:50:23

CWE-400

apache

www.cve.org

apache http server

http/2

memory allocation

security update

7.1 High

AI Score

Confidence

High

0.732 High

EPSS

Percentile

98.1%

JSON

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.

CNA Affected

[
  {
    "defaultStatus": "unaffected",
    "product": "Apache HTTP Server",
    "vendor": "Apache Software Foundation",
    "versions": [
      {
        "lessThanOrEqual": "2.4.57",
        "status": "affected",
        "version": "2.4.17",
        "versionType": "semver"
      }
    ]
  }
]