CVE-2023-53209
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's mac80211_hwsim WiFi simulation module. If exploited, it could cause kernel crashes or denial of service on systems using this module. The vulnerability affects Linux systems with the mac80211_hwsim module loaded, typically in testing or development environments.
💻 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 leading to system crash and denial of service, potentially requiring physical access to restart the system.
Likely Case
System instability or crash requiring reboot, with possible data loss for unsaved work.
If Mitigated
Minimal impact if module not loaded or system not using WiFi simulation features.
🎯 Exploit Status
Exploitation requires specific conditions: mac80211_hwsim module loaded and ability to trigger the vulnerable code path. Likely requires local access or WiFi simulation testing.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel branches (commits: 0cc80943ef518a1c51a1111e9346d1daf11dd545, a8a20fed3e05b3a6866c5c58855deaf3c217ccd6, d0124848c7940aba73492e282506b32a13f2e30e)
Vendor Advisory: https://git.kernel.org/stable/c/0cc80943ef518a1c51a1111e9346d1daf11dd545
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 mac80211_hwsim module is not loaded unless needed for testing.
🔧 Temporary Workarounds
Disable mac80211_hwsim module
LinuxPrevent loading of the vulnerable module if not required for system operation
echo 'blacklist mac80211_hwsim' > /etc/modprobe.d/blacklist-mac80211_hwsim.conf
rmmod mac80211_hwsim
🧯 If You Can't Patch
- Ensure mac80211_hwsim module is not loaded in production environments
- Restrict access to systems where WiFi simulation/testing is performed
🔍 How to Verify
Check if Vulnerable:
Check if mac80211_hwsim module is loaded: lsmod | grep mac80211_hwsimCheck Version:
uname -rVerify Fix Applied:
Check kernel version is patched and module not loaded: uname -r && lsmod | grep mac80211_hwsim📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- NULL pointer dereference errors in kernel logs
Network Indicators:
- Unusual WiFi simulation traffic if module in use
SIEM Query:
kernel: *NULL pointer dereference* OR kernel: *mac80211_hwsim* AND (panic OR oops)