NULL Pointer Dereference Affecting apache/httpd package, versions [,2.4.48)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
22.64% (97th percentile)

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  • Snyk IDSNYK-UNMANAGED-APACHEHTTPD-3007310
  • published12 Jan 2022
  • disclosed15 Jun 2021
  • creditUnknown

Introduced: 15 Jun 2021

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

How to fix?

Upgrade apache/httpd to version 2.4.48 or higher.

Overview

Affected versions of this package are vulnerable to NULL Pointer Dereference. 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

CVSS Scores

version 3.1