The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict request-header length, which allows remote attackers to cause a denial of service (memory consumption) via crafted CONTINUATION frames in an HTTP/2 request.
https://github.com/apache/httpd/commit/29c63b786ae028d82405421585e91283c8fa0da3
http://www.securityfocus.com/bid/94650
https://www.exploit-db.com/exploits/40909/
http://www.securitytracker.com/id/1037388
http://packetstormsecurity.com/files/140023/Apache-HTTPD-Web-Server-2.4.23-Memory-Exhaustion.html
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03725en_us
https://security.gentoo.org/glsa/201701-36
https://www.tenable.com/security/tns-2017-04
https://support.apple.com/HT208221
https://access.redhat.com/errata/RHSA-2017:1414
https://access.redhat.com/errata/RHSA-2017:1413
https://access.redhat.com/errata/RHSA-2017:1161
http://rhn.redhat.com/errata/RHSA-2017-1415.html
https://security.netapp.com/advisory/ntap-20180423-0001/
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/re3d27b6250a[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Ccvs.httpd.apache.org%3E
Source: MITRE
Published: 2016-12-05
Updated: 2021-06-06
Type: CWE-20
Base Score: 5
Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P
Impact Score: 2.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 3.9
Severity: HIGH