CVE-2022-32250
📋 TL;DR
This vulnerability in the Linux kernel's netfilter component allows a local user with namespace creation privileges to escalate to root via a use-after-free condition. It affects Linux kernel versions up to 5.18.1. Attackers need local access and ability to create user/net namespaces.
💻 Affected Systems
- Linux kernel
📦 What is this software?
Fedora by Fedoraproject
Fedora by Fedoraproject
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to root, allowing complete system compromise, data theft, persistence establishment, and lateral movement.
Likely Case
Privileged attackers or compromised low-privilege accounts escalate to root, gaining full control over affected systems.
If Mitigated
With proper namespace restrictions and least privilege, impact limited to isolated containers or namespaces.
🎯 Exploit Status
Exploit requires local access and namespace creation capabilities. Multiple public references discuss exploitation details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel 5.18.2 and later
Vendor Advisory: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=520778042ccca019f3ffa136dd0ca565c486cedd
Restart Required: Yes
Instructions:
1. Update Linux kernel to 5.18.2 or later. 2. Reboot system. 3. Check with distribution vendor for backported patches if using older kernel series.
🔧 Temporary Workarounds
Restrict namespace creation
linuxLimit ability to create user and network namespaces to prevent exploitation.
sysctl -w user.max_user_namespaces=0
sysctl -w user.max_net_namespaces=0
Disable nf_tables module
linuxUnload the vulnerable nf_tables kernel module if not required.
rmmod nf_tables
🧯 If You Can't Patch
- Implement strict namespace restrictions using sysctl or container runtime configurations
- Apply principle of least privilege - restrict CAP_NET_ADMIN and namespace creation capabilities
🔍 How to Verify
Check if Vulnerable:
Check kernel version: uname -r. If version is 5.18.1 or earlier, system is vulnerable.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is 5.18.2 or later: uname -r📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages related to nf_tables
- Unexpected privilege escalation events
- Namespace creation by unauthorized users
Network Indicators:
- None - local exploitation only
SIEM Query:
source="kernel" AND ("nf_tables" OR "use-after-free") OR event="privilege_escalation"🔗 References
- http://www.openwall.com/lists/oss-security/2022/06/03/1
- http://www.openwall.com/lists/oss-security/2022/06/04/1
- http://www.openwall.com/lists/oss-security/2022/06/20/1
- http://www.openwall.com/lists/oss-security/2022/07/03/5
- http://www.openwall.com/lists/oss-security/2022/07/03/6
- http://www.openwall.com/lists/oss-security/2022/08/25/1
- http://www.openwall.com/lists/oss-security/2022/09/02/9
- https://blog.theori.io/research/CVE-2022-32250-linux-kernel-lpe-2022/
- https://bugzilla.redhat.com/show_bug.cgi?id=2092427
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/net/netfilter?id=520778042ccca019f3ffa136dd0ca565c486cedd
- https://github.com/theori-io/CVE-2022-32250-exploit
- https://lists.debian.org/debian-lts-announce/2022/07/msg00000.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MO6Y3TC4WUUNKRP7OQA26OVTZTPCS6F2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UIZTJOJCVVEJVOQSCHE6IJQKMPISHQ5L/
- https://security.netapp.com/advisory/ntap-20220715-0005/
- https://www.debian.org/security/2022/dsa-5161
- https://www.debian.org/security/2022/dsa-5173
- https://www.openwall.com/lists/oss-security/2022/05/31/1
- http://www.openwall.com/lists/oss-security/2022/06/03/1
- http://www.openwall.com/lists/oss-security/2022/06/04/1
- http://www.openwall.com/lists/oss-security/2022/06/20/1
- http://www.openwall.com/lists/oss-security/2022/07/03/5
- http://www.openwall.com/lists/oss-security/2022/07/03/6
- http://www.openwall.com/lists/oss-security/2022/08/25/1
- http://www.openwall.com/lists/oss-security/2022/09/02/9
- https://blog.theori.io/research/CVE-2022-32250-linux-kernel-lpe-2022/
- https://bugzilla.redhat.com/show_bug.cgi?id=2092427
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/net/netfilter?id=520778042ccca019f3ffa136dd0ca565c486cedd
- https://github.com/theori-io/CVE-2022-32250-exploit
- https://lists.debian.org/debian-lts-announce/2022/07/msg00000.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MO6Y3TC4WUUNKRP7OQA26OVTZTPCS6F2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UIZTJOJCVVEJVOQSCHE6IJQKMPISHQ5L/
- https://security.netapp.com/advisory/ntap-20220715-0005/
- https://www.debian.org/security/2022/dsa-5161
- https://www.debian.org/security/2022/dsa-5173
- https://www.openwall.com/lists/oss-security/2022/05/31/1
