In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 protocol.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2018-11763 from the MITRE CVE dictionary dictionary and NIST NVD.
| CVSS3 Base Score | 7.5 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | None |
| Availability Impact | High |
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Software Collections for Red Hat Enterprise Linux 6 (httpd24-httpd) | RHSA-2018:3558 | 2018-11-13 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 (httpd24-httpd) | RHSA-2018:3558 | 2018-11-13 |
| Platform | Package | State |
|---|---|---|
| Red Hat Virtualization 4 | httpd | Not affected |
| Red Hat Mobile Application Platform On-Premise 4 | httpd | Will not fix |
| Red Hat JBoss Web Server 3 | httpd | Affected |
| Red Hat JBoss EWS 2 | httpd | Not affected |
| Red Hat JBoss EAP 6 | httpd | Not affected |
| Red Hat JBoss EAP 5 | httpd | Not affected |
| Red Hat JBoss Core Services 1 | httpd | Affected |
| Red Hat Enterprise Linux 7 | httpd | Not affected |
| Red Hat Enterprise Linux 6 | httpd | Not affected |
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