ArchLinux: 202106-23: apache: denial of service | LinuxSecurity.com
Arch Linux Security Advisory ASA-202106-23
==========================================

Severity: High
Date    : 2021-06-09
CVE-ID  : CVE-2021-31618
Package : apache
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-2041

Summary
=======

The package apache before version 2.4.48-1 is vulnerable to denial of
service.

Resolution
==========

Upgrade to 2.4.48-1.

# pacman -Syu "apache>=2.4.48-1"

The problem has been fixed upstream in version 2.4.48.

Workaround
==========

None.

Description
===========

A security issue has been found in the Apache HTTP Server (httpd)
before version 2.4.48. The 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, an 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 footer. This led to a NULL pointer
dereference on initialised memory, reliably crashing the child process.
Since such a triggering HTTP/2 request is easy to craft and submit,
this can be exploited for denial of service (DoS) of the server.

Impact
======

A remote attacker could crash the HTTP server using a crafted HTTP/2
request.

References
==========

https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2021-31618
https://svn.apache.org/viewvc?view=revision&revision=1889759
https://security.archlinux.org/CVE-2021-31618

ArchLinux: 202106-23: apache: denial of service

June 11, 2021
The package apache before version 2.4.48-1 is vulnerable to denial of service

Summary

A security issue has been found in the Apache HTTP Server (httpd) before version 2.4.48. The 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, an 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 footer. This led to a NULL pointer dereference on initialised memory, reliably crashing the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited for denial of service (DoS) of the server.

Resolution

Upgrade to 2.4.48-1.
# pacman -Syu "apache>=2.4.48-1"
The problem has been fixed upstream in version 2.4.48.

References

https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2021-31618 https://svn.apache.org/viewvc?view=revision&revision=1889759 https://security.archlinux.org/CVE-2021-31618

Severity
CVE-ID : CVE-2021-31618
Package : apache
Type : denial of service
Remote : Yes
Link : https://security.archlinux.org/AVG-2041

Impact

A remote attacker could crash the HTTP server using a crafted HTTP/2 request.

Workaround

None.

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