SB2021083126 - Red Hat Enterprise Linux 8.2 update for kernel 



SB2021083126 - Red Hat Enterprise Linux 8.2 update for kernel

Published: August 31, 2021 Updated: February 8, 2024

Security Bulletin ID SB2021083126
Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Medium 25% Low 75%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) Buffer overflow (CVE-ID: CVE-2021-22543)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in Linux kernel when handling VM_IO|VM_PFNMAP vmas in KVM. A local user can  can bypass RO checks and cause the pages to get freed while still accessible by the VMM and guest. As a result, an attacker with the ability to start and control a VM to read/write random pages of memory, can trigger memory corruption and execute arbitrary code with elevated privileges.



2) Race condition (CVE-ID: CVE-2021-32399)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition  for removal of the HCI controller within net/bluetooth/hci_request.c in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.


3) Out-of-bounds write (CVE-ID: CVE-2021-22555)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error when processing untrusted input in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.


4) Race condition (CVE-ID: CVE-2021-3609)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition in the CAN BCM networking protocol (net/can/bcm.c) in the Linux kernel ranging from version 2.6.25 to mainline 5.13-rc6. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.


Remediation

Install update from vendor's website.