CVE-2025-38642
📋 TL;DR
This CVE describes a kernel warning triggered in the Linux kernel's WiFi subsystem when using monitor mode on certain wireless devices. The vulnerability doesn't allow direct exploitation but could potentially lead to denial of service or be used as part of a larger attack chain. It affects Linux systems with specific WiFi hardware configurations.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic or system crash leading to denial of service, potentially disrupting critical services on affected systems.
Likely Case
Kernel warning messages in system logs and potential instability of WiFi monitor interfaces, but no direct code execution.
If Mitigated
Minor system log noise with no operational impact if warnings are properly handled by the kernel.
🎯 Exploit Status
Exploitation requires local access and specific WiFi hardware configuration; primarily a stability issue rather than security vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 1e10ded6b0f9b0eeefaacbb6c6c6afff3f702812, c57e5b9819dfd16d709bcd6cb633301ed0829a66, or ff15498ebaa49c5429a74e70a1951dede60cd14c
Vendor Advisory: https://git.kernel.org/stable/c/1e10ded6b0f9b0eeefaacbb6c6c6afff3f702812
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable monitor mode on vulnerable hardware
allPrevent triggering the WARN_ON by avoiding monitor mode interfaces on affected WiFi devices
# Check for monitor interfaces: iwconfig | grep Mode:Monitor
# Disable monitor mode by not creating monitor interfaces
🧯 If You Can't Patch
- Avoid using monitor mode on WiFi devices that lack WANT_MONITOR_VIF support
- Monitor system logs for kernel warnings and restart affected services if instability occurs
🔍 How to Verify
Check if Vulnerable:
Check kernel version and monitor system logs for 'WARN_ON' messages related to mac80211 monitor interfaces when using monitor modeCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits and no WARN_ON messages appear when using monitor mode interfaces📡 Detection & Monitoring
Log Indicators:
- Kernel WARN_ON messages in dmesg or /var/log/kern.log related to 'mac80211' and 'monitor'
Network Indicators:
- Unusual WiFi monitor interface behavior or disconnections
SIEM Query:
source="kernel" AND "WARN_ON" AND "mac80211" AND "monitor"