CVE-2018-11763 Denial of service in Apache HTTP Server

Medium 5.9 Published 25 Sep 2018 Updated 17 Sep 2024

Attackers can exhaust server resources via large HTTP/2 SETTINGS frames, causing denial of service; mitigated by disabling HTTP/2.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2018-11763?

CVE-2018-11763 is a medium-severity denial of service vulnerability in Apache Http Server, published on 25 Sep 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Which versions are affected by CVE-2018-11763?

It affects 9 products.

Linux distribution packages (12)

`apache2` SUSE:Enterprise Storage 4	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Module for Server Applications 15	All versions	`2.4.33-3.6.1`
`apache2` SUSE:Linux Enterprise Server 12 SP2-BCL	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Server 12 SP2-LTSS	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Server 12 SP3	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Server 12 SP4	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Server for SAP Applications 12 SP2	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Server for SAP Applications 12 SP3	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Server for SAP Applications 12 SP4	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Software Development Kit 12 SP3	All versions	`2.4.23-29.27.2`
`apache2` SUSE:Linux Enterprise Software Development Kit 12 SP4	All versions	`2.4.23-29.27.2`
`apache2` SUSE:OpenStack Cloud 7	All versions	`2.4.23-29.27.2`

Products include Apache Http Server, Canonical Ubuntu Linux, Netapp Storage Automation Store, Oracle Enterprise Manager Ops Center, Oracle Hospitality Guest Access, Oracle Instantis Enterprisetrack and 3 more.

How do I fix CVE-2018-11763?

Change a configuration setting.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2018-11763 being exploited?

There is no known exploitation of CVE-2018-11763 in the wild and no public exploit code.

All Apache Http Server vulnerabilities

Sources

Also known as ALPINE-CVE-2018-11763, CLEANSTART-2026-WK36713, DEBIAN-CVE-2018-11763, GHSA-c8x9-mqh7-g47j, SUSE-SU-2018:3101-1, SUSE-SU-2018:3582-1 and 2 more.