CVE-2021-47348
📋 TL;DR
This CVE describes a buffer over-read vulnerability in the AMD display driver component of the Linux kernel. An attacker could exploit this to read kernel memory beyond the intended buffer, potentially leading to information disclosure or system corruption. Systems running affected Linux kernel versions with AMD graphics hardware are vulnerable.
💻 Affected Systems
- Linux kernel with AMD display driver (drm/amd/display)
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory corruption leading to privilege escalation, system crash, or information disclosure of sensitive kernel data.
Likely Case
System instability, crashes, or information disclosure of non-sensitive kernel memory.
If Mitigated
Minimal impact if kernel memory protections are in place, but still potential for information disclosure.
🎯 Exploit Status
Exploitation requires local access and ability to interact with the display driver. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing the git commits referenced in the CVE
Vendor Advisory: https://git.kernel.org/stable/c/06888d571b513cbfc0b41949948def6cb81021b2
Restart Required: Yes
Instructions:
1. Update Linux kernel to a patched version. 2. Check with your distribution for specific kernel updates. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable AMD display driver
linuxTemporarily disable the affected AMD display driver module
modprobe -r amdgpu
echo 'blacklist amdgpu' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict local user access to systems with AMD graphics
- Implement strict privilege separation and limit user permissions
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if AMD display driver is loaded: 'lsmod | grep amdgpu' and 'uname -r'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated beyond vulnerable versions and check git commit history includes the fix📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes related to display driver
- dmesg errors mentioning amdgpu or display
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for kernel panic logs or amdgpu driver errors in system logs🔗 References
- https://git.kernel.org/stable/c/06888d571b513cbfc0b41949948def6cb81021b2
- https://git.kernel.org/stable/c/3b2b93a485fb7a970bc8b5daef16f4cf579d172f
- https://git.kernel.org/stable/c/44c7c901cb368a9f2493748f213b247b5872639f
- https://git.kernel.org/stable/c/c5b518f4b98dbb2bc31b6a55e6aaa1e0e2948f2e
- https://git.kernel.org/stable/c/06888d571b513cbfc0b41949948def6cb81021b2
- https://git.kernel.org/stable/c/3b2b93a485fb7a970bc8b5daef16f4cf579d172f
- https://git.kernel.org/stable/c/44c7c901cb368a9f2493748f213b247b5872639f
- https://git.kernel.org/stable/c/c5b518f4b98dbb2bc31b6a55e6aaa1e0e2948f2e
