Rapid7 Vulnerability & Exploit Database

Amazon Linux AMI 2: CVE-2021-31618: Security patch for httpd, mod_http2 (Multiple Advisories)

Free InsightVM Trial No Credit Card Necessary
Watch Demo See how it all works
Back to Search

Amazon Linux AMI 2: CVE-2021-31618: Security patch for httpd, mod_http2 (Multiple Advisories)

Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:P)
Published
06/15/2021
Created
06/25/2021
Added
06/24/2021
Modified
09/30/2022

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.

Solution(s)

  • amazon-linux-ami-2-upgrade-httpd
  • amazon-linux-ami-2-upgrade-httpd-debuginfo
  • amazon-linux-ami-2-upgrade-httpd-devel
  • amazon-linux-ami-2-upgrade-httpd-filesystem
  • amazon-linux-ami-2-upgrade-httpd-manual
  • amazon-linux-ami-2-upgrade-httpd-tools
  • amazon-linux-ami-2-upgrade-mod_http2
  • amazon-linux-ami-2-upgrade-mod_http2-debuginfo
  • amazon-linux-ami-2-upgrade-mod_ldap
  • amazon-linux-ami-2-upgrade-mod_md
  • amazon-linux-ami-2-upgrade-mod_proxy_html
  • amazon-linux-ami-2-upgrade-mod_session
  • amazon-linux-ami-2-upgrade-mod_ssl

References

insightVM

Advanced vulnerability management analytics and reporting.
Key Features
Free InsightVM Trial View All Features

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;