CVE-2025-38692
📋 TL;DR
A Linux kernel exFAT filesystem driver vulnerability allows infinite loops when processing corrupted directory cluster chains. This affects systems using exFAT filesystems and can lead to denial of service. The vulnerability requires filesystem corruption to trigger.
💻 Affected Systems
- Linux kernel with exFAT filesystem support
📦 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
System becomes unresponsive due to kernel infinite loops, requiring hard reboot and potentially causing data loss or filesystem corruption.
Likely Case
Local denial of service when accessing corrupted exFAT filesystems, requiring system restart to recover.
If Mitigated
Minimal impact with proper filesystem integrity checks and monitoring in place.
🎯 Exploit Status
Requires filesystem corruption and specific conditions. Not remotely exploitable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 4c3cda20c4cf1871e27868d08fda06b79bc7d568 and related
Vendor Advisory: https://git.kernel.org/stable/c/4c3cda20c4cf1871e27868d08fda06b79bc7d568
Restart Required: No
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel. 3. Reboot if kernel update requires it.
🔧 Temporary Workarounds
Disable exFAT mounting
LinuxPrevent mounting of exFAT filesystems to avoid triggering the vulnerability
echo 'blacklist exfat' >> /etc/modprobe.d/blacklist-exfat.conf
update-initramfs -u
🧯 If You Can't Patch
- Avoid mounting untrusted exFAT filesystems
- Implement filesystem integrity monitoring and regular checks
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if exFAT module is loaded: lsmod | grep exfat && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits or is newer than vulnerable versions📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing exFAT errors
- System becoming unresponsive when accessing exFAT filesystems
- High CPU usage from kernel processes
Network Indicators:
- None - local filesystem vulnerability
SIEM Query:
source="kernel" AND ("exfat" OR "filesystem corruption")🔗 References
- https://git.kernel.org/stable/c/4c3cda20c4cf1871e27868d08fda06b79bc7d568
- https://git.kernel.org/stable/c/868f23286c1a13162330fa6c614fe350f78e3f82
- https://git.kernel.org/stable/c/99f9a97dce39ad413c39b92c90393bbd6778f3fd
- https://git.kernel.org/stable/c/aa8fe7b7b73d4c9a41bb96cb3fb3092f794ecb33
- https://git.kernel.org/stable/c/e2066ca3ef49a30920d8536fa366b2a183a808ee
