CVE-2018-20784 Denial of service in n/a

What is CVE-2018-20784?

CVE-2018-20784 is a critical denial of service vulnerability in Canonical Ubuntu Linux, published on 22 Feb 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.

Weakness: CWE-835

Which versions are affected by CVE-2018-20784?

It affects 4 products.

Products include Canonical Ubuntu Linux, Linux kernel, Redhat Enterprise Linux, Redhat Enterprise Linux for Real Time.

How do I fix CVE-2018-20784?

Apply the vendor's patch.

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-2018-20784 being exploited?

There is no known exploitation of CVE-2018-20784 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2018-20784, GHSA-qg2g-rfcv-qffx, UBUNTU-CVE-2018-20784.