CVE-2021-31440 Privilege escalation in Kernel

What is CVE-2021-31440?

CVE-2021-31440 is a high-severity vulnerability in Linux kernel, published on 21 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.11.15. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs prior to executing them. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-13661.

Weakness: CWE-682

Which versions are affected by CVE-2021-31440?

It affects 10 products.

Products include Linux kernel, Netapp Cloud Backup, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410s Firmware, Netapp H500e Firmware and 4 more.

How do I fix CVE-2021-31440?

Apply the vendor's patch.

Is CVE-2021-31440 being exploited?

There is no known exploitation of CVE-2021-31440 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

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 A-189614572, DEBIAN-CVE-2021-31440, GHSA-c57j-pq55-rh2x, PUB-A-189614572, UBUNTU-CVE-2021-31440.