RHSA-2022:4835HighCVSS 7.8

Red Hat Security Advisory: kernel-rt security and bug fix update

Published
May 31, 2022
Last Modified
August 10, 2026

🔗 CVE IDs covered (3)

CVE-2021-4037 →CVE-2021-20322 →CVE-2022-27666 →

📋 Description

CVE-2021-4037 — kernel: security regression for CVE-2018-13405 CVE-2021-20322 — kernel: new DNS Cache Poisoning Attack based on ICMP fragment needed packets replies CVE-2022-27666 — kernel: buffer overflow in IPsec ESP transformation code

🎯 Affected products32

  • Red Hat Enterprise Linux NFV EUS (v.8.4)
  • Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-0:4.18.0-305.49.1.rt7.121.el8_4.src as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-0:4.18.0-305.49.1.rt7.121.el8_4.src as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-core-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-core-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debug-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debug-core-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-core-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debug-debuginfo-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-debuginfo-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debug-devel-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-devel-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debug-kvm-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-modules-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-modules-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debug-modules-extra-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debug-modules-extra-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debuginfo-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debuginfo-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-debuginfo-common-x86_64-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-debuginfo-common-x86_64-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-devel-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-devel-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • kernel-rt-kvm-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-modules-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux NFV EUS (v.8.4)
  • kernel-rt-modules-0:4.18.0-305.49.1.rt7.121.el8_4.x86_64 as a component of Red Hat Enterprise Linux RT EUS (v.8.4)
  • +2 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Workaround: The given exploit needs CAP_NET_ADMIN to set up IPsec SA and a user namespace is used to get that capability, so disabling unprivileged user namespaces gives some protection. ~~~ On non-containerized deployments of Red Hat Enterprise Linux 8, you can disable user namespaces by setting user.max_user_namespaces to 0: # echo "user.max_user_namespaces=0" > /etc/sysctl.d/userns.conf # sysctl -p /etc/sysctl.d/userns.conf On containerized deployments, such as Red Hat OpenShift Container Platform, do not use this mitigation as the functionality is needed to be enabled. ~~~ Note: If the target system is already using IPsec and has SA configured, then no additional privileges are needed to exploit the issue.

🔗 References (6)