CVE-2025-37952
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's ksmbd module allows attackers to potentially crash the kernel or execute arbitrary code. This affects Linux systems with ksmbd (SMB server) enabled, particularly those sharing files via SMB protocol. Attackers could exploit this to gain elevated privileges or cause denial of service.
💻 Affected Systems
- Linux kernel with ksmbd module
📦 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 →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
System instability, kernel crashes, or denial of service affecting SMB file sharing functionality.
If Mitigated
Limited impact if ksmbd module is disabled or not in use, with potential for crashes only affecting SMB services.
🎯 Exploit Status
Exploitation requires race condition timing and access to SMB services. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 16727e442568a46d9cca69fe2595896de86e120d or related fixes
Vendor Advisory: https://git.kernel.org/stable/c/16727e442568a46d9cca69fe2595896de86e120d
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify ksmbd module loads correctly after reboot.
🔧 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 network access
linuxUse firewall rules to block access to SMB ports
iptables -A INPUT -p tcp --dport 445 -j DROP
iptables -A INPUT -p udp --dport 445 -j DROP
🧯 If You Can't Patch
- Disable ksmbd module if not required for business operations
- Implement strict network segmentation and limit SMB access to trusted hosts only
🔍 How to Verify
Check if Vulnerable:
Check if ksmbd module is loaded: lsmod | grep ksmbdCheck Version:
uname -rVerify Fix Applied:
Check kernel version after update and verify ksmbd module version matches patched kernel📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- ksmbd crash logs in dmesg
- Unexpected SMB connection failures
Network Indicators:
- Unusual SMB traffic patterns
- Multiple rapid SMB connection attempts
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "ksmbd")