Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 10 Jun 2021 14:38:14 +0000
From: John Helmert III <>
Subject: Re: CVE-2021-31618: Apache httpd: NULL pointer
 dereference on specially crafted HTTP/2 request

On Wed, Jun 09, 2021 at 11:11:00PM +0200, Christophe JAILLET wrote:
> CVE-2021-31618: NULL pointer dereference on specially crafted HTTP/2 request
> Severity: important
> Vendor: The Apache Software Foundation
> Versions Affected:
> 2.4.47
> httpd 
> Description:
> Apache HTTP Server 2.4.47
> 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 affected versions prior to 2.4.47

The announcement on the website indicates the affected versions for
CVE-2021-31618 are <2.4.48 and in the below table it indicates <=2.4.48
are affected. Both of these are different from the mail advisory, can
you clarify the affected versions, please?

> Mitigation:
> none
> Credit:
> Apache HTTP server would like to thank  LI ZHI XIN from NSFocus for reporting this.
> References:

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.