CVE-2023-4134
📋 TL;DR
A use-after-free vulnerability in the cyttsp4_core driver of the Linux kernel allows a local user to crash the system by exploiting improper timer handling during device cleanup. This affects Linux systems using the Cypress TrueTouch touchscreen driver. The vulnerability requires local access to the system.
💻 Affected Systems
- Linux kernel
📦 What is this software?
Fedora by Fedoraproject
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 leading to kernel panic and complete system crash, causing denial of service and potential data loss.
Likely Case
Local denial of service through kernel panic, requiring system reboot to restore functionality.
If Mitigated
Limited to denial of service with no data compromise if proper access controls restrict local user privileges.
🎯 Exploit Status
Exploitation requires local access and knowledge of driver internals. No public exploits have been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel commit 6c0f8fa5f0dd or later; distribution-specific patches available
Vendor Advisory: https://access.redhat.com/security/cve/CVE-2023-4134
Restart Required: Yes
Instructions:
1. Update kernel package using distribution's package manager. 2. For RHEL: yum update kernel. 3. For Ubuntu: apt update && apt upgrade linux-image-generic. 4. Reboot system to load patched kernel.
🔧 Temporary Workarounds
Disable cyttsp4_core driver
linuxPrevent loading of vulnerable driver module
echo 'blacklist cyttsp4_core' >> /etc/modprobe.d/blacklist-cyttsp4.conf
rmmod cyttsp4_core
🧯 If You Can't Patch
- Restrict local user access to systems with vulnerable driver loaded
- Implement strict access controls and monitor for suspicious local activity
🔍 How to Verify
Check if Vulnerable:
Check if cyttsp4_core module is loaded: lsmod | grep cyttsp4_coreCheck Version:
uname -rVerify Fix Applied:
Check kernel version after update: uname -r and verify it matches patched version from vendor advisory📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/messages or dmesg
- System crash/reboot events without clear cause
Network Indicators:
- None - local exploitation only
SIEM Query:
source="kernel" AND ("panic" OR "Oops") AND "cyttsp4"