CVEvulnerability

CVE-2021-31618

7.5 HIGH Published 2021-06-15 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-06-15
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected])
5.0 MEDIUM — AV:N/AC:L/Au:N/C:N/I:N/A:P
Weaknesses
CWE-476

Description

Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released.

Affected configurations

• apache http server 1.15.17 • apache http server 2.4.47 • fedoraproject fedora 33 • fedoraproject fedora 34 • debian debian linux 9.0 • debian debian linux 10.0 • oracle enterprise manager ops center 12.4.0.0 • oracle instantis enterprisetrack 17.1 • oracle instantis enterprisetrack 17.2 • oracle instantis enterprisetrack 17.3 • oracle zfs storage appliance kit 8.8

Related

Weakness · CWE (1)

  • CWE-476 NULL Pointer Dereference weakness

References