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Apache HTTPD: mod_http2, DoS attack by exhausting h2 workers. (CVE-2019-9517)

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Apache HTTPD: mod_http2, DoS attack by exhausting h2 workers. (CVE-2019-9517)

Severity
8
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:C)
Published
08/13/2019
Created
08/17/2019
Added
08/16/2019
Modified
12/09/2024

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)

  • apache-httpd-upgrade-latest

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