SB2021081720 - SUSE update for the Linux Kernel (Live Patch 10 for SLE 12 SP5)



SB2021081720 - SUSE update for the Linux Kernel (Live Patch 10 for SLE 12 SP5)

Published: August 17, 2021

Security Bulletin ID SB2021081720
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 67% Low 33%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


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

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear


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-2021-3609)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green


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.


3) Out-of-bounds write (CVE-ID: CVE-2021-37576)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


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

The vulnerability exists due to a boundary error in arch/powerpc/kvm/book3s_rtas.c in the Linux kernel through 5.13.5 on the powerpc platform. An attacker on KVM guest OS can cause host OS memory corruption via rtas_args.nargs and execute arbitrary code on the host OS.


Remediation

Install update from vendor's website.