CVE-2021-47604
📋 TL;DR
This CVE describes an out-of-bounds read vulnerability in the Linux kernel's vduse driver. An attacker could read kernel memory beyond allocated bounds, potentially exposing sensitive information. Systems running affected Linux kernel versions with vduse functionality enabled are vulnerable.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory disclosure leading to information leakage, potential privilege escalation if combined with other vulnerabilities, or system instability/crash.
Likely Case
Information disclosure from kernel memory, potentially exposing sensitive data or system state information.
If Mitigated
Minimal impact if vduse functionality is disabled or systems are properly segmented with limited user access.
🎯 Exploit Status
Requires local access and ability to interact with vduse interface. Exploitation would need to trigger the specific code path with crafted parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits dc1db0060c02d119fd4196924eff2d1129e9a442 and ebbbc5fea3f648175df1aa3f127c78eb0252cc2a
Vendor Advisory: https://git.kernel.org/stable/c/dc1db0060c02d119fd4196924eff2d1129e9a442
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 vduse module
linuxPrevent loading of the vulnerable vduse kernel module
echo 'blacklist vduse' >> /etc/modprobe.d/blacklist-vduse.conf
rmmod vduse
🧯 If You Can't Patch
- Disable vduse functionality if not required
- Restrict access to users who could interact with vduse interfaces
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if vduse module is loaded: 'uname -r' and 'lsmod | grep vduse'Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits or check if vduse module is disabled📡 Detection & Monitoring
Log Indicators:
- Kernel oops or crash logs related to vduse
- Unexpected memory access patterns in kernel logs
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Search for kernel logs containing 'vduse' and 'BUG' or 'Oops'