CVE-2021-34866

Name: CVE-2021-34866
Creator: NVD / NIST
Published: 2022-01-25T16:15:08.45+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.97%

Last modified Jun 17, 2026

CVE-2021-34866 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.14-rc3. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. EPSS estimates a 0.97% chance of exploitation in the next 30 days.

Description

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.14-rc3. 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, which can result in a type confusion condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-14689.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.97%

57.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 5.8, < 5.10.62
Linux	Linux Kernel	>= 5.11, < 5.13.14
Netapp	H410c Firmware	All versions
Netapp	H300s Firmware	All versions
Netapp	H500s Firmware	All versions
Netapp	H700s Firmware	All versions
Netapp	H300e Firmware	All versions
Netapp	H500e Firmware	All versions
Netapp	H700e Firmware	All versions
Netapp	H410s Firmware	All versions

References

https://security.netapp.com/advisory/ntap-20220217-0008/Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-1148/Third Party Advisory, VDB Entry
https://security.netapp.com/advisory/ntap-20220217-0008/Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-1148/Third Party Advisory, VDB Entry

Timeline

Published: Jan 25, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34866?

How severe is CVE-2021-34866?

CVE-2021-34866 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.97% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34866?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34866?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST