Linux Distros Unpatched Vulnerability : CVE-2021-38166

high Nessus Plugin ID 223990

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket. NOTE: exploitation might be impractical without the CAP_SYS_ADMIN capability. (CVE-2021-38166)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2021-38166

https://ubuntu.com/security/CVE-2021-38166

Plugin Details

Severity: High

ID: 223990

File Name: unpatched_CVE_2021_38166.nasl

Version: 1.2

Type: local

Agent: unix

Family: Misc.

Published: 3/5/2025

Updated: 8/10/2025

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2021-38166

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-gcp-edge, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-gke-4.15, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.8, p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:canonical:ubuntu_linux:linux-hwe, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.6, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.8, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-oem, cpe:/o:centos:centos:8, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-azure-edge, p-cpe:/a:redhat:enterprise_linux:kernel, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-azure, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:centos:centos:kernel-rt, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-edge, p-cpe:/a:centos:centos:kernel, p-cpe:/a:canonical:ubuntu_linux:linux-riscv, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-raspi2

Required KB Items: Host/OS/identifier, Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 8/7/2021

Reference Information

CVE: CVE-2021-38166