---
id: CVE-2024-0193
title: >-
  Kernel: netfilter: use-after-free in nft_trans_gc_catchall_sync leads to
  privilege escalation
summary: >-
  A use-after-free flaw was found in the netfilter subsystem of the Linux
  kernel. If the catchall element is garbage-collected when the pipapo set is
  removed, the element can be deactivated twice. This can cause a use-after-free
  issue on a…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-416
vendor: Red Hat
product: kernel
affected:
  - kernel (all versions)
  - kernel (all versions)
  - kernel (all versions)
  - kernel (all versions)
  - kernel-rt (all versions)
  - kernel (all versions)
  - kernel-rt (all versions)
  - openshift-logging/cluster-logging-operator-bundle (all versions)
  - openshift-logging/cluster-logging-rhel9-operator (all versions)
  - openshift-logging/elasticsearch6-rhel9 (all versions)
  - openshift-logging/elasticsearch-operator-bundle (all versions)
  - openshift-logging/elasticsearch-proxy-rhel9 (all versions)
  - openshift-logging/elasticsearch-rhel9-operator (all versions)
  - openshift-logging/eventrouter-rhel9 (all versions)
  - openshift-logging/fluentd-rhel9 (all versions)
  - openshift-logging/log-file-metric-exporter-rhel9 (all versions)
  - openshift-logging/logging-curator5-rhel9 (all versions)
  - openshift-logging/logging-loki-rhel9 (all versions)
  - openshift-logging/logging-view-plugin-rhel9 (all versions)
  - openshift-logging/loki-operator-bundle (all versions)
  - openshift-logging/loki-rhel9-operator (all versions)
  - openshift-logging/lokistack-gateway-rhel9 (all versions)
  - openshift-logging/opa-openshift-rhel9 (all versions)
  - openshift-logging/vector-rhel9 (all versions)
  - kernel
  - kernel
  - kernel-rt
  - kernel
  - kernel-rt
  - kernel-rt (all versions)
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2024-07-02T13:17:27.203202Z'
exploitAvailable: true
published: '2024-01-02'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T21:07:31.422Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2024-0193'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2024:1018'
    label: 'RHSA-2024:1018'
  - url: 'https://access.redhat.com/errata/RHSA-2024:1019'
    label: 'RHSA-2024:1019'
  - url: 'https://access.redhat.com/errata/RHSA-2024:1248'
    label: 'RHSA-2024:1248'
  - url: 'https://access.redhat.com/errata/RHSA-2024:2094'
    label: 'RHSA-2024:2094'
  - url: 'https://access.redhat.com/errata/RHSA-2024:4412'
    label: 'RHSA-2024:4412'
  - url: 'https://access.redhat.com/errata/RHSA-2024:4415'
    label: 'RHSA-2024:4415'
  - url: 'https://access.redhat.com/security/cve/CVE-2024-0193'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2255653'
    label: RHBZ#2255653
tags:
  - cve.org
  - exploit-available
epss: 0.00836
epssPercentile: 0.57851
ingestedAt: '2026-11-05T21:36:00.594Z'
---

## Overview

A use-after-free flaw was found in the netfilter subsystem of the Linux kernel. If the catchall element is garbage-collected when the pipapo set is removed, the element can be deactivated twice. This can cause a use-after-free issue on an NFT_CHAIN object or NFT_OBJECT object, allowing a local unprivileged user with CAP_NET_ADMIN capability to escalate their privileges on the system.

## Affected

- `kernel (all versions)`
- `kernel (all versions)`
- `kernel (all versions)`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `openshift-logging/cluster-logging-operator-bundle (all versions)`
- `openshift-logging/cluster-logging-rhel9-operator (all versions)`
- `openshift-logging/elasticsearch6-rhel9 (all versions)`
- `openshift-logging/elasticsearch-operator-bundle (all versions)`
- `openshift-logging/elasticsearch-proxy-rhel9 (all versions)`
- `openshift-logging/elasticsearch-rhel9-operator (all versions)`
- `openshift-logging/eventrouter-rhel9 (all versions)`
- `openshift-logging/fluentd-rhel9 (all versions)`
- `openshift-logging/log-file-metric-exporter-rhel9 (all versions)`
- `openshift-logging/logging-curator5-rhel9 (all versions)`
- `openshift-logging/logging-loki-rhel9 (all versions)`
- `openshift-logging/logging-view-plugin-rhel9 (all versions)`
- `openshift-logging/loki-operator-bundle (all versions)`
- `openshift-logging/loki-rhel9-operator (all versions)`
- `openshift-logging/lokistack-gateway-rhel9 (all versions)`
- `openshift-logging/opa-openshift-rhel9 (all versions)`
- `openshift-logging/vector-rhel9 (all versions)`
- `kernel`
- `kernel`
- `kernel-rt`
- `kernel`
- `kernel-rt`
- `kernel-rt (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

In order to trigger the issue, it requires the ability to create user/net namespaces.

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.