FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

varnish -- HTTP/2 Rapid Reset Attack

Affected packages
varnish7 < 7.4.2
varnish6 < 6.6.3


VuXML ID f25a34b1-910d-11ee-a1a2-641c67a117d8
Discovery 2023-11-13
Entry 2023-12-02

Varnish Cache Project reports:

A denial of service attack can be performed on Varnish Cache servers that have the HTTP/2 protocol turned on. An attacker can create a large volume of streams and immediately reset them without ever reaching the maximum number of concurrent streams allowed for the session, causing the Varnish server to consume unnecessary resources processing requests for which the response will not be delivered.


CVE Name CVE-2023-44487