Skip to main content

CVE-2021-22600

6.6
MEDIUMCVSS v3.1 Base Score
0.18%
LOW RiskEPSS (39th percentile)
KEV

A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755

Published: 1/26/2022
Modified: 10/24/2025
Back to CVE Lookup

ACTIVELY EXPLOITED IN THE WILD

This vulnerability is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

Vulnerability Name:

Linux Kernel Privilege Escalation Vulnerability

Vendor / Product:

Linux Kernel

Required Action:

Apply updates per vendor instructions.

Due Date: 5/2/2022(OVERDUE)
Added to KEV:

4/11/2022

Notes:

https://nvd.nist.gov/vuln/detail/CVE-2021-22600

Vulnerability Summary

CVSS v3 Score

6.6MEDIUM

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

CVSS v2 Score

7.2

AV:L/AC:L/Au:N/C:C/I:C/A:C

EPSS Score (Exploitation Probability)

0.18%LOW Exploitation Risk
39th percentile

This vulnerability has a 0.18% probability of being exploited in the next 30 days, ranking higher than 39% of all scored CVEs.

CWE Classification

Related Vulnerabilities

Same Weakness Type(CWE-415)

CVE-2025-62215HIGH 7

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Kernel allows an authorized attacker to elevate privileges locally.

11/11/2025
CVE-2024-45402HIGH 8.6

Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. When parsing a spoofed TLS handshake message, picotls (specifically, bindings within picotls that call the crypto libraries) may attempt to free the same memory twice. This double free occurs during the disposal of multiple objects without any intervening calls to malloc Typically, this triggers the malloc implementation to detect the error and abort the process. However, depending on the internals of malloc and the crypto backend being used, the flaw could potentially lead to a use-after-free scenario, which might allow for arbitrary code execution. The vulnerability is addressed with commit 9b88159ce763d680e4a13b6e8f3171ae923a535d.

10/11/2024
CVE-2023-49937CRITICAL 9.8

An issue was discovered in SchedMD Slurm 22.05.x, 23.02.x, and 23.11.x. Because of a double free, attackers can cause a denial of service or possibly execute arbitrary code. The fixed versions are 22.05.11, 23.02.7, and 23.11.1.

12/14/2023
CVE-2023-45666HIGH 7.3

stb_image is a single file MIT licensed library for processing images. It may look like `stbi__load_gif_main` doesn’t give guarantees about the content of output value `*delays` upon failure. Although it sets `*delays` to zero at the beginning, it doesn’t do it in case the image is not recognized as GIF and a call to `stbi__load_gif_main_outofmem` only frees possibly allocated memory in `*delays` without resetting it to zero. Thus it would be fair to say the caller of `stbi__load_gif_main` is responsible to free the allocated memory in `*delays` only if `stbi__load_gif_main` returns a non null value. However at the same time the function may return null value, but fail to free the memory in `*delays` if internally `stbi__convert_format` is called and fails. Thus the issue may lead to a memory leak if the caller chooses to free `delays` only when `stbi__load_gif_main` didn’t fail or to a double-free if the `delays` is always freed

10/21/2023
CVE-2023-35784CRITICAL 9.8

A double free or use after free could occur after SSL_clear in OpenBSD 7.2 before errata 026 and 7.3 before errata 004, and in LibreSSL before 3.6.3 and 3.7.x before 3.7.3. NOTE: OpenSSL is not affected.

6/16/2023

Similar SeverityMEDIUM

CVE-2026-34926MEDIUM 6.7

A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.

5/21/2026
CVE-2026-45498MEDIUM 4

Microsoft Defender Denial of Service Vulnerability

5/20/2026
CVE-2026-40243MEDIUM 4.8

Incus is a system container and virtual machine manager. In versions before 7.0.0, broken TLS validation logic in the OVN database connection logic can allow connections to an attacker's OVN database. The OVN client implementations disable Go standard TLS server verification and replace it with custom peer-certificate verification logic. That replacement verifier does not anchor trust in the configured CA certificate. Instead, it constructs the verification root set from certificates supplied by the peer during the handshake, so the configured CA is parsed but not used as the trust anchor for the final verification decision. In OVN-enabled deployments that use these SSL database connection paths, an attacker able to impersonate or intercept the OVN endpoint on the management network can present a rogue self-signed certificate chain, and Incus will accept this certificate as valid. This issue defeats the intended CA-based trust model for OVN database connections and permits endpoint impersonation by an active attacker in a suitable network position. This issue is fixed in version 7.0.0.

5/6/2026
CVE-2026-40197MEDIUM 6.5

Incus is a system container and virtual machine manager. In versions before 7.0.0, missing validation logic in the storage volume import logic allows an authenticated user with access to the storage volume feature to cause the Incus daemon to crash. The custom volume backup import subsystem contains a nil-pointer dereference vulnerability during import operations. In the snapshot import loop, the daemon iterates over entries from `srcBackup.Config.VolumeSnapshots` and assumes that each slice element is initialized, then dereferences fields such as `Name`, `Config`, `Description`, `CreatedAt`, and `ExpiresAt` without first validating the element itself. Because the yaml unmarshaler accepts explicit null array elements from an attacker-controlled index.yaml and converts them into nil pointers inside the slice, an attacker can supply a backup archive containing a null entry in the volume_snapshots array. This causes a nil-pointer dereference during custom volume import and terminates the daemon, resulting in denial of service on the affected node. Repeated use of this issue can be used to keep Incus offline, causing a denial of service. This issue is fixed in version 7.0.0.

5/6/2026
CVE-2026-8033MEDIUM 5.3

A vulnerability has been found in PicoTronica e-Clinic Healthcare System ECHS 5.7. This affects an unknown function of the file /cdemos/echs/api/v2/ of the component Response Header Handler. Such manipulation leads to information disclosure. The attack may be performed from remote. The exploit has been disclosed to the public and may be used. Upgrading to version 5.7.1 mitigates this issue. It is suggested to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

5/6/2026