By specially crafting HTTP/2 requests, workers would be allocated 60 seconds longer than necessary, leading to worker exhaustion and a denial of service. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33).
https://www.tenable.com/security/tns-2019-09
https://usn.ubuntu.com/3783-1/
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03909en_us
https://security.netapp.com/advisory/ntap-20180926-0007/
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2018-1333
https://access.redhat.com/errata/RHSA-2019:0367
https://access.redhat.com/errata/RHSA-2019:0366