CVE-2023-53480
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's kobject subsystem allows local attackers to cause a kernel panic (denial of service) by registering a kset without initializing its ktype field. This affects systems running vulnerable Linux kernel versions where local users can load kernel modules or interact with kobject interfaces.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Local attacker causes kernel panic leading to system crash and denial of service, potentially disrupting critical services.
Likely Case
Local user or misconfigured kernel module triggers kernel panic, causing system instability or crash.
If Mitigated
With proper access controls, only privileged users can trigger the vulnerability, limiting impact to authorized personnel.
🎯 Exploit Status
Exploitation requires local access and knowledge of kernel programming to trigger the NULL pointer dereference.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with commits: 039ec9db2d30032eafa365f5f89b30eca5322b05, 1a772881bc059c596d8ca587cbd2a233edce3d3b, 48aebbe801e78a8932404c122ed0e880ccedc220, 4d0fe8c52bb3029d83e323c961221156ab98680b, 5df5829158513134ddcaf2184d9286eda7b0bb18
Vendor Advisory: https://git.kernel.org/stable/c/
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Restrict kernel module loading
linuxPrevent unauthorized users from loading kernel modules that could trigger the vulnerability
echo 1 > /proc/sys/kernel/modules_disabled
sysctl -w kernel.modules_disabled=1
Limit local user privileges
linuxRestrict access to users who could potentially trigger kernel operations
usermod -aG restricted_users username
chmod 750 /sys/kernel/*
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized users from loading kernel modules or accessing kernel interfaces
- Monitor system logs for kernel panic events and investigate any unauthorized kernel module loading attempts
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from kernel git repository. Vulnerable if running unpatched kernel with kobject subsystem.Check Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched version and test kset registration with uninitialized ktype (requires kernel development knowledge).📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference errors in kernel logs
- Call traces showing kobject_get_ownership or kset_register
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kobject_get_ownership" OR "kset_register")🔗 References
- https://git.kernel.org/stable/c/039ec9db2d30032eafa365f5f89b30eca5322b05
- https://git.kernel.org/stable/c/1a772881bc059c596d8ca587cbd2a233edce3d3b
- https://git.kernel.org/stable/c/48aebbe801e78a8932404c122ed0e880ccedc220
- https://git.kernel.org/stable/c/4d0fe8c52bb3029d83e323c961221156ab98680b
- https://git.kernel.org/stable/c/5df5829158513134ddcaf2184d9286eda7b0bb18
- https://git.kernel.org/stable/c/964e025ceefdf75da46b0133d0c2790de451aeec
- https://git.kernel.org/stable/c/f3f6bf22a4f5ba649cf26ae4670de5c7f861bdef
