RHSA-2021:0003HighCVSS 6.7

Red Hat Security Advisory: kernel security and bug fix update

Published
January 4, 2021
Last Modified
November 5, 2026

🔗 CVE IDs covered (1)

CVE-2020-25211 →

📋 Description

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 (v. 8)
  • Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-0:4.18.0-240.10.1.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-0:4.18.0-240.10.1.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat CodeReady Linux Builder (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat CodeReady Linux Builder (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.x86_64 as a component of Red Hat CodeReady Linux Builder (v. 8)
  • bpftool-debuginfo-0:4.18.0-240.10.1.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-0:4.18.0-240.10.1.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-0:4.18.0-240.10.1.el8_3.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-0:4.18.0-240.10.1.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-abi-whitelists-0:4.18.0-240.10.1.el8_3.noarch as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-core-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-core-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-core-0:4.18.0-240.10.1.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-core-0:4.18.0-240.10.1.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-0:4.18.0-240.10.1.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-0:4.18.0-240.10.1.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-core-0:4.18.0-240.10.1.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-core-0:4.18.0-240.10.1.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kernel-debug-core-0:4.18.0-240.10.1.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • +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: 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 (4)