CVE-2023-53197
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's USB UHCI driver when using debugfs_lookup() without proper cleanup. The vulnerability allows attackers to gradually exhaust kernel memory over time, potentially leading to system instability or denial of service. All Linux systems using the affected kernel versions with USB UHCI functionality are affected.
💻 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 →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
Sustained exploitation could lead to kernel memory exhaustion, causing system crashes, denial of service, or unpredictable system behavior that might enable further attacks.
Likely Case
Gradual memory leak over time leading to system performance degradation, potential application failures, or system instability requiring reboots.
If Mitigated
With proper monitoring and memory limits, impact is limited to performance degradation that can be detected and addressed before critical failure.
🎯 Exploit Status
Exploitation requires local access and debugfs permissions. The vulnerability is a resource exhaustion issue rather than a direct code execution vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in stable kernel commits: 0a3f82c79c86278e7f144564b1cb6cc5c3657144, 9cb88847b8b86f132309030022a23dca895b6f61, c6af1dbc99ad37bf67c8703982df4d7f12d256c1, e529aeb771aef1402c899b6b405610ef444d5d88
Vendor Advisory: https://git.kernel.org/stable/c/0a3f82c79c86278e7f144564b1cb6cc5c3657144
Restart Required: Yes
Instructions:
1. Update to a patched kernel version from your distribution's repositories. 2. Reboot the system to load the new kernel. 3. Verify the fix is applied by checking kernel version.
🔧 Temporary Workarounds
Disable debugfs access
allPrevent unauthorized access to debugfs which is required to trigger the vulnerability
mount -o remount,nodebugfs /sys/kernel/debug
chmod 000 /sys/kernel/debug
Restrict debugfs permissions
allLimit access to debugfs to trusted users only
chmod 700 /sys/kernel/debug
chown root:root /sys/kernel/debug
🧯 If You Can't Patch
- Implement strict access controls to debugfs interface
- Monitor system memory usage for unusual patterns and implement alerting
- Consider disabling USB UHCI functionality if not required
🔍 How to Verify
Check if Vulnerable:
Check kernel version against affected versions and verify if USB UHCI driver is loaded: 'lsmod | grep uhci' and 'mount | grep debugfs'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to a patched version and check that the specific commit hash is included in your kernel📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- System memory exhaustion warnings in syslog
- Application failures due to memory allocation errors
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("out of memory" OR "oom-killer" OR "memory allocation failure")