CVE-2021-47571
📋 TL;DR
This is a use-after-free vulnerability in the Linux kernel's RTL8192E wireless driver. It allows attackers with local access to potentially execute arbitrary code or cause denial of service by exploiting memory corruption after device disconnection. Systems using the staging rtl8192e driver are affected.
💻 Affected Systems
- Linux kernel with rtl8192e staging 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
Local privilege escalation to kernel-level code execution, potentially leading to full system compromise.
Likely Case
Kernel panic or system crash causing denial of service.
If Mitigated
No impact if driver not loaded or system properly patched.
🎯 Exploit Status
Requires local access and specific conditions to trigger the use-after-free condition during PCI device disconnection.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel stable releases containing commits: 2e1ec01af2c7139c6a600bbfaea1a018b35094b6, 8d0163cec7de995f9eb9c3128c83fb84f0cb1c64, 9186680382934b0e7529d3d70dcc0a21d087683b, b535917c51acc97fb0761b1edec85f1f3d02bda4, bca19bb2dc2d89ce60c4a4a6e59609d4cf2e13ef
Vendor Advisory: https://git.kernel.org/stable/c/2e1ec01af2c7139c6a600bbfaea1a018b35094b6
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from distribution vendor. 2. Rebuild kernel if using custom kernel. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable staging rtl8192e driver
linuxPrevent loading of the vulnerable driver module
echo 'blacklist rtl8192e' >> /etc/modprobe.d/blacklist-rtl8192e.conf
rmmod rtl8192e
🧯 If You Can't Patch
- Disable or remove the staging rtl8192e driver module
- Restrict local access to systems using vulnerable driver
🔍 How to Verify
Check if Vulnerable:
Check if rtl8192e module is loaded: lsmod | grep rtl8192eCheck Version:
uname -rVerify Fix Applied:
Check kernel version against patched releases and verify rtl8192e module not loaded or updated📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes during PCI device disconnection
- Unexpected kernel panics
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for kernel panic logs or module loading events related to rtl8192e🔗 References
- https://git.kernel.org/stable/c/2e1ec01af2c7139c6a600bbfaea1a018b35094b6
- https://git.kernel.org/stable/c/8d0163cec7de995f9eb9c3128c83fb84f0cb1c64
- https://git.kernel.org/stable/c/9186680382934b0e7529d3d70dcc0a21d087683b
- https://git.kernel.org/stable/c/b535917c51acc97fb0761b1edec85f1f3d02bda4
- https://git.kernel.org/stable/c/bca19bb2dc2d89ce60c4a4a6e59609d4cf2e13ef
- https://git.kernel.org/stable/c/c0ef0e75a858cbd8618b473f22fbca36106dcf82
- https://git.kernel.org/stable/c/d43aecb694b10db9a4228ce2d38b5ae8de374443
- https://git.kernel.org/stable/c/e27ee2f607fe6a9b923ef1fc65461c0613c97594
- https://git.kernel.org/stable/c/2e1ec01af2c7139c6a600bbfaea1a018b35094b6
- https://git.kernel.org/stable/c/8d0163cec7de995f9eb9c3128c83fb84f0cb1c64
- https://git.kernel.org/stable/c/9186680382934b0e7529d3d70dcc0a21d087683b
- https://git.kernel.org/stable/c/b535917c51acc97fb0761b1edec85f1f3d02bda4
- https://git.kernel.org/stable/c/bca19bb2dc2d89ce60c4a4a6e59609d4cf2e13ef
- https://git.kernel.org/stable/c/c0ef0e75a858cbd8618b473f22fbca36106dcf82
- https://git.kernel.org/stable/c/d43aecb694b10db9a4228ce2d38b5ae8de374443
- https://git.kernel.org/stable/c/e27ee2f607fe6a9b923ef1fc65461c0613c97594
