CVE-2024-53186
📋 TL;DR
A race condition in the Linux kernel's ksmbd SMB server module leads to use-after-free vulnerability during SMB request handling. This allows attackers with network access to potentially crash the kernel or execute arbitrary code. Systems running affected Linux kernel versions with ksmbd enabled are vulnerable.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash or arbitrary code execution with kernel privileges, resulting in complete system compromise.
Likely Case
Kernel crash causing denial of service and potential system instability.
If Mitigated
Limited impact if ksmbd is disabled or proper network segmentation prevents access.
🎯 Exploit Status
Exploitation requires triggering the race condition which may be timing-dependent. No public exploit code available at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 96261adb998a3b513468b6ce17dbec76be5507d4, 9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e, a96f9eb7add30ba0fafcfe7b7aca090978196800, or f20b77f7897e6aab9ce5527e6016ad2be5d70a33
Vendor Advisory: https://git.kernel.org/stable/c/96261adb998a3b513468b6ce17dbec76be5507d4
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Reboot system. 3. Verify ksmbd module loads correctly if needed.
🔧 Temporary Workarounds
Disable ksmbd module
linuxPrevent loading of vulnerable ksmbd kernel module
echo 'blacklist ksmbd' >> /etc/modprobe.d/blacklist-ksmbd.conf
rmmod ksmbd
Block SMB ports
linuxBlock SMB network access at firewall
iptables -A INPUT -p tcp --dport 445 -j DROP
iptables -A INPUT -p tcp --dport 139 -j DROP
🧯 If You Can't Patch
- Disable ksmbd module and block SMB ports at network perimeter
- Implement strict network segmentation to isolate SMB servers
🔍 How to Verify
Check if Vulnerable:
Check if ksmbd module is loaded: lsmod | grep ksmbd. If loaded and kernel version is unpatched, system is vulnerable.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits and ksmbd module loads without errors.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- ksmbd crash logs in dmesg
- KASAN use-after-free reports
Network Indicators:
- Multiple rapid SMB connection attempts
- Unusual SMB traffic patterns
SIEM Query:
source="kernel" AND ("panic" OR "KASAN" OR "use-after-free") AND "ksmbd"