CVE-2022-50533
📋 TL;DR
This CVE describes a null pointer dereference vulnerability in the Linux kernel's WiFi subsystem (mac80211). When a device fails to associate with an access point that doesn't have link 0, the kernel crashes due to improper handling of cleared data structures. This affects Linux systems using the mac80211 WiFi stack.
💻 Affected Systems
- Linux kernel
⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially requiring physical or remote reboot.
Likely Case
System crash or instability when WiFi association fails under specific conditions, causing temporary denial of service.
If Mitigated
Minor disruption requiring manual intervention to restart network services or reboot.
🎯 Exploit Status
Exploitation requires ability to trigger failed WiFi association with specific AP configurations. Likely requires local network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 78a6a43aaf87180ec7425a2a90468e1b4d09a1ec, bb7743955a929e44b308cc3f63f8cc03873c1bee, c695dfba8dfb82dc7ace4f22be088916cbf621ca
Vendor Advisory: https://git.kernel.org/stable/c/78a6a43aaf87180ec7425a2a90468e1b4d09a1ec
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable WiFi or use wired networking
linuxAvoid using WiFi interfaces to prevent triggering the vulnerability
sudo ip link set wlan0 down
sudo systemctl stop NetworkManager
Avoid problematic AP configurations
linuxPrevent association with access points that lack link 0
🧯 If You Can't Patch
- Implement network segmentation to limit WiFi access to trusted networks only
- Monitor system logs for kernel panic events and have reboot procedures ready
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with distribution security advisories. Vulnerable if using kernel before fix commits.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits: 78a6a43aaf87180ec7425a2a90468e1b4d09a1ec or related fixes📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference errors in dmesg
- System crash/reboot events
Network Indicators:
- Failed WiFi association attempts
- Unusual network disconnections
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kernel panic" OR "mac80211")