RHSA-2021:0184HighCVSS 6.7

Red Hat Security Advisory: kernel security and bug fix update

Published
January 19, 2021
Last Modified
November 5, 2026

🔗 CVE IDs covered (2)

CVE-2020-16166 →CVE-2020-25211 →

📋 Description

CVE-2020-16166 — kernel: information exposure in drivers/char/random.c and kernel/time/timer.c CVE-2020-25211 — kernel: Local buffer overflow in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c

🎯 Affected products122

  • Red Hat CodeReady Linux Builder EUS (v. 8.1)
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-0:4.18.0-147.38.1.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-0:4.18.0-147.38.1.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat CodeReady Linux Builder EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat CodeReady Linux Builder EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.x86_64 as a component of Red Hat CodeReady Linux Builder EUS (v. 8.1)
  • bpftool-debuginfo-0:4.18.0-147.38.1.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-0:4.18.0-147.38.1.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-0:4.18.0-147.38.1.el8_1.src as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-0:4.18.0-147.38.1.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-abi-whitelists-0:4.18.0-147.38.1.el8_1.noarch as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-core-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-core-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-core-0:4.18.0-147.38.1.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-core-0:4.18.0-147.38.1.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-0:4.18.0-147.38.1.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-0:4.18.0-147.38.1.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-core-0:4.18.0-147.38.1.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-core-0:4.18.0-147.38.1.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • kernel-debug-core-0:4.18.0-147.38.1.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)
  • +92 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: To mitigate this issue, prevent module nf_conntrack_netlink from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically. Alternatively, if nf_conntrack_netlink is being used, on Red Hat Enterprise Linux 8, you can disable unprivileged 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

🔗 References (5)