CVE-2021-4218 Denial of service in kernel

What is CVE-2021-4218?

CVE-2021-4218 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Aug 2022. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A flaw was found in the Linux kernel’s implementation of reading the SVC RDMA counters. Reading the counter sysctl panics the system. This flaw allows a local attacker with local access to cause a denial of service while the system reboots. The issue is specific to CentOS/RHEL.

Weakness: CWE-665

Which versions are affected by CVE-2021-4218?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-4218?

No fix has been published for CVE-2021-4218 yet. Limit exposure of the affected software until one is available.

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-2021-4218 being exploited?

There is no known exploitation of CVE-2021-4218 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

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

Also known as GHSA-q6f7-v272-hqqq, UBUNTU-CVE-2021-4218.