vulnerability

Oracle Linux: CVE-2021-3600: ELSA-2021-4356: kernel security, bug fix, and enhancement update (MODERATE)

Severity
7
CVSS
(AV:L/AC:L/Au:S/C:C/I:C/A:C)
Published
Jun 23, 2021
Added
Nov 18, 2021
Modified
Dec 3, 2025

Description

It was discovered that the eBPF implementation in the Linux kernel did not properly track bounds information for 32 bit registers when performing div and mod operations. A local attacker could use this to possibly execute arbitrary code.
A flaw was found in the Linux kernel’s eBPF verification code, where the eBPF 32-bit div/mod source register truncation could lead to out-of-bounds reads and writes. By default, accessing the eBPF verifier is only possible to privileged users with CAP_SYS_ADMIN. This flaw allows a local user who can run eBPF instructions to crash the system or possibly escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Solution

oracle-linux-upgrade-kernel
Title
Rapid7 Labs

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