RHSA-2023:4696HighCVSS 7.8

Red Hat Security Advisory: kernel security update

Published
August 22, 2023
Last Modified
November 7, 2026

🔗 CVE IDs covered (2)

CVE-2023-20593 →CVE-2023-32233 →

📋 Description

CVE-2023-20593 — hw: amd: Cross-Process Information Leak CVE-2023-32233 — kernel: netfilter: use-after-free in nf_tables when processing batch requests can lead to privilege escalation

🎯 Affected products27

  • Red Hat Enterprise Linux Server AUS (v. 7.6)
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • bpftool-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-0:3.10.0-957.105.1.el7.src as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-abi-whitelists-0:3.10.0-957.105.1.el7.noarch as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-debug-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • kernel-debug-devel-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • kernel-debuginfo-common-x86_64-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-debuginfo-common-x86_64-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • kernel-devel-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-doc-0:3.10.0-957.105.1.el7.noarch as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-tools-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-tools-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-tools-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • kernel-tools-libs-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • kernel-tools-libs-devel-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • perf-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • perf-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • perf-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)
  • python-perf-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • python-perf-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server AUS (v. 7.6)
  • python-perf-debuginfo-0:3.10.0-957.105.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server Optional AUS (v. 7.6)

✅ 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: 1. This flaw can be mitigated by preventing the affected netfilter (nf_tables) kernel module from being loaded. For instructions on how to blacklist a kernel module, please see https://access.redhat.com/solutions/41278. 2. If the module cannot be disabled, on non-containerized deployments of Red Hat Enterprise Linux, the mitigation is to disable user namespaces: ``` # 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 the second mitigation (disabling user namespaces) as the functionality is needed to be enabled. The first mitigation (blacklisting nf_tables) is still viable for containerized deployments, providing the environment is not using netfilter.

🔗 References (5)