CVE-2022-50408
📋 TL;DR
This is a use-after-free vulnerability in the Linux kernel's Broadcom FullMAC wireless driver (brcmfmac). It allows an attacker to potentially execute arbitrary code or cause a denial of service by exploiting a race condition in network packet transmission. Systems using affected Linux kernel versions with Broadcom wireless chipsets are vulnerable.
💻 Affected Systems
- Linux kernel with brcmfmac driver
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory corruption leading to arbitrary code execution with kernel privileges, potentially resulting in full system compromise.
Likely Case
Kernel panic or system crash causing denial of service, requiring system reboot.
If Mitigated
No impact if patched or if wireless interface is disabled.
🎯 Exploit Status
Exploitation requires local network access and precise timing to trigger the race condition. No public exploits have been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 1613a7b24f1a, 232d59eca07f, 27574a3f421c, 3f42faf6db43, 49c742afd60f
Vendor Advisory: https://git.kernel.org/stable/c/1613a7b24f1a7467cb727ba3ec77c9a808383560
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 wireless interface
linuxTemporarily disable the vulnerable wireless interface to prevent exploitation
sudo ip link set wlan0 down
sudo nmcli radio wifi off
Blacklist brcmfmac module
linuxPrevent loading of the vulnerable driver module
echo 'blacklist brcmfmac' | sudo tee /etc/modprobe.d/blacklist-brcmfmac.conf
sudo update-initramfs -u
sudo reboot
🧯 If You Can't Patch
- Disable wireless networking entirely if not required
- Implement network segmentation to limit potential attack surface
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if brcmfmac module is loaded: lsmod | grep brcmfmac && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check for presence of fix commits in kernel source📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN use-after-free reports in dmesg
- brcmfmac driver crash logs
Network Indicators:
- Unexpected wireless interface resets
- Abnormal network traffic patterns
SIEM Query:
source="kernel" AND ("KASAN" OR "use-after-free" OR "brcmfmac")🔗 References
- https://git.kernel.org/stable/c/1613a7b24f1a7467cb727ba3ec77c9a808383560
- https://git.kernel.org/stable/c/232d59eca07f6ea27307022a33d226aff373bd02
- https://git.kernel.org/stable/c/27574a3f421c3a1694d0207f37c6bbf23d66978e
- https://git.kernel.org/stable/c/3f42faf6db431e04bf942d2ebe3ae88975723478
- https://git.kernel.org/stable/c/49c742afd60f552fce7799287080db02bffe1db2
- https://git.kernel.org/stable/c/c369836cff98d3877f98c98e15c0151462812d96
- https://git.kernel.org/stable/c/d79f4d903e14dde822c60b5fd3bedc5a289d25df
- https://git.kernel.org/stable/c/e01d96494a9de0f48b1167f0494f6d929fa773ed
