CVE-2021-4204 Memory corruption in kernel

What is CVE-2021-4204?

CVE-2021-4204 is a high-severity memory corruption vulnerability in Debian Debian Linux, 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

An out-of-bounds (OOB) memory access flaw was found in the Linux kernel's eBPF due to an Improper Input Validation. This flaw allows a local attacker with a special privilege to crash the system or leak internal information.

Weakness: CWE-119, CWE-20

Which versions are affected by CVE-2021-4204?

It affects 8 products.

Products include Debian Debian Linux, Linux kernel, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500s Firmware and 2 more.

How do I fix CVE-2021-4204?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-4204 being exploited?

There is no known exploitation of CVE-2021-4204 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

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

Also known as DEBIAN-CVE-2021-4204, GHSA-5gx9-gr87-492v, ROOT-OS-DEBIAN-11-CVE-2021-4204, UBUNTU-CVE-2021-4204, USN-5219-1.