What is RHSA-2021:0004?

RHSA-2021:0004 is a security advisory published by Red Hat Product Security with High severity. Red Hat Security Advisory: kernel-rt security and bug fix update

Which CVE IDs does RHSA-2021:0004 cover?

RHSA-2021:0004 covers the following CVE IDs: CVE-2020-25211. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of RHSA-2021:0004?

RHSA-2021:0004 has a CVSS v3 base score of 6.7, published by Red Hat Product Security.

Which products are affected by RHSA-2021:0004?

RHSA-2021:0004 affects 32 products, including: Red Hat Enterprise Linux Real Time (v. 8); Red Hat Enterprise Linux Real Time for NFV (v. 8); kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.src as a component of Red Hat Enterprise Linux Real Time (v. 8); kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.src as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8); kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8); and others — see the full list on the advisory page.

RHSA-2021:0004HighCVSS 6.7

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

Vendor

Red Hat Product Security

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 products32

Red Hat Enterprise Linux Real Time (v. 8)
Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.src as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.src as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-core-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-core-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debug-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-core-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debug-core-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-debuginfo-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debug-debuginfo-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-devel-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debug-devel-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-kvm-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-modules-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debug-modules-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debug-modules-extra-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debug-modules-extra-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debuginfo-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debuginfo-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-debuginfo-common-x86_64-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-debuginfo-common-x86_64-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-devel-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-devel-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-kvm-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
kernel-rt-modules-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time (v. 8)
kernel-rt-modules-0:4.18.0-240.10.1.rt7.64.el8_3.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV (v. 8)
+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: 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

🔗 CVE IDs covered (1)

📋 Description

🎯 Affected products32

✅ Remediation

🔗 References (5)