Rapid7 Vulnerability & Exploit Database

IBM HTTP Server: CVE-2019-9517: mod_http2, DoS attack by exhausting h2 workers.

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

IBM HTTP Server: CVE-2019-9517: mod_http2, DoS attack by exhausting h2 workers.

Severity
8
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:C)
Published
08/13/2019
Created
11/06/2019
Added
11/05/2019
Modified
11/22/2019

Description

Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.

Solution(s)

  • ibm-http_server-apply-fix-pack-9_0_5_1

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

;