Homepage

NULL Pointer Dereference The advisory has been revoked - it doesn't affect any version of package mod_md  (opens in a new tab)

Threat Intelligence

EPSS
51.49% (99th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-RHEL8-MODMD-1888084
  • published1 Nov 2021
  • disclosed4 Jun 2021
Report a new vulnerability Found a mistake?

Introduced: 4 Jun 2021

CVE-2021-31618  (opens in a new tab)
CWE-476  (opens in a new tab)

Amendment

The Red Hat security team deemed this advisory irrelevant for RHEL:8.

NVD Description

Note: Versions mentioned in the description apply only to the upstream mod_md package and not the mod_md package as distributed by RHEL.

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.

References