A denial of service attack can be performed against Varnish Cache servers by specially formatting the reason phrase of the backend response status line. In order to execute an attack, the attacker would have to be able to influence the HTTP/1 responses that the Varnish Server receives from its configured backends. A successful attack would cause the Varnish Server to assert and automatically restart.
Upstream issue & fix:
Created varnish tracking bugs for this issue:
Affects: epel-all [bug 2118571]
Affects: fedora-all [bug 2118570]
Created varnish-modules tracking bugs for this issue:
Affects: fedora-all [bug 2118572]
Created varnish:6.0/varnish tracking bugs for this issue:
Affects: fedora-all [bug 2118573]
Created varnish:6.0/varnish-modules tracking bugs for this issue:
Affects: fedora-all [bug 2118574]
FEDORA-2022-1fa6d1ed2f has been pushed to the Fedora 36 stable repository.
If problem still persists, please make note of it in this bug report.
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):