CVE-2022-29581
📋 TL;DR
A local privilege escalation vulnerability in the Linux kernel's net/sched subsystem allows attackers with local access to gain root privileges. This affects Linux kernel versions 4.14 through 5.17. The vulnerability stems from improper reference count updates that can be exploited to cause privilege escalation.
💻 Affected Systems
- Linux Kernel
📦 What is this software?
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 →Ubuntu Linux by Canonical
Ubuntu Linux by Canonical
Ubuntu Linux by Canonical
Ubuntu Linux by Canonical
Ubuntu Linux by Canonical
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains full root privileges, enabling complete system compromise, data theft, persistence mechanisms, and lateral movement.
Likely Case
Local user or compromised service account escalates to root, enabling installation of malware, credential harvesting, and privilege maintenance.
If Mitigated
With proper access controls and minimal local user accounts, impact is limited to specific compromised services rather than full system takeover.
🎯 Exploit Status
Exploit requires local access and knowledge of kernel exploitation techniques. Public exploit code exists in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel 5.18 and later
Vendor Advisory: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3db09e762dc79584a69c10d74a6b98f89a9979f8
Restart Required: Yes
Instructions:
1. Update kernel to version 5.18 or later. 2. For distributions with backported patches, apply security updates. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Restrict local user access
linuxLimit local user accounts and implement strict access controls to reduce attack surface.
Disable unnecessary kernel modules
linuxRemove or blacklist unnecessary kernel modules to reduce attack surface.
echo 'blacklist sch_netem' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Implement strict access controls and limit local user accounts
- Use SELinux/AppArmor to restrict kernel access and contain potential privilege escalation
🔍 How to Verify
Check if Vulnerable:
Check kernel version with 'uname -r' and compare to affected range (4.14-5.17).Check Version:
uname -rVerify Fix Applied:
Verify kernel version is 5.18 or later with 'uname -r' and check for applied security patches in distribution update logs.📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events
- Kernel panic or oops messages related to net/sched
- Unusual root activity from non-privileged users
Network Indicators:
- None - local exploit only
SIEM Query:
source="kernel" AND ("net/sched" OR "sch_" OR "CVE-2022-29581")🔗 References
- http://packetstormsecurity.com/files/167386/Kernel-Live-Patch-Security-Notice-LSN-0086-1.html
- http://packetstormsecurity.com/files/168191/Kernel-Live-Patch-Security-Notice-LSN-0089-1.html
- http://www.openwall.com/lists/oss-security/2022/05/18/2
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3db09e762dc79584a69c10d74a6b98f89a9979f8
- https://kernel.dance/#3db09e762dc79584a69c10d74a6b98f89a9979f8
- https://security.netapp.com/advisory/ntap-20220629-0005/
- https://www.debian.org/security/2022/dsa-5173
- http://packetstormsecurity.com/files/167386/Kernel-Live-Patch-Security-Notice-LSN-0086-1.html
- http://packetstormsecurity.com/files/168191/Kernel-Live-Patch-Security-Notice-LSN-0089-1.html
- http://www.openwall.com/lists/oss-security/2022/05/18/2
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3db09e762dc79584a69c10d74a6b98f89a9979f8
- https://kernel.dance/#3db09e762dc79584a69c10d74a6b98f89a9979f8
- https://security.netapp.com/advisory/ntap-20220629-0005/
- https://www.debian.org/security/2022/dsa-5173
