CVE-2021-3444

Severity CVSS v4.0:

Pending analysis

Type:

CWE-125 Out-of-bounds Read

Publication date:

23/03/2021

Last modified:

02/12/2021

Description

The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.80 HIGH
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

7.80

Severity 3.x

HIGH

Vector 2.0

AV:L/AC:L/Au:N/C:P/I:P/A:P CVSS v2.0 Severity and Metrics:

Base Score: 4.60 MEDIUM
Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): Physical
Availability (A): Physical

Base Score 2.0

4.60

Severity 2.0

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::		5.4.101 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.5.0 (including)	5.10.19 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.11 (including)	5.11.2 (excluding)
cpe:2.3:o:debian:debian_linux:9.0:::::::*
cpe:2.3:o:canonical:ubuntu_linux:14.04::::esm:::
cpe:2.3:o:canonical:ubuntu_linux:16.04::::lts:::
cpe:2.3:o:canonical:ubuntu_linux:18.04::::lts:::
cpe:2.3:o:canonical:ubuntu_linux:20.04::::lts:::

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-3444

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools