CVE-2023-53049
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's USB Type-C Connector System Software Interface (UCSI) driver. When ucsi_init() fails during system initialization, subsequent ACPI events can trigger a NULL pointer dereference in ucsi_connector_change(), potentially causing a kernel panic or system crash. This affects Linux systems with UCSI support enabled.
💻 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 →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
Kernel panic leading to system crash and denial of service, potentially requiring physical access to restart affected systems.
Likely Case
System instability or crash when USB Type-C events occur during or after failed UCSI initialization, resulting in temporary denial of service.
If Mitigated
Minimal impact if systems are patched or don't use UCSI functionality; crashes would be contained to affected systems without lateral movement.
🎯 Exploit Status
Exploitation requires ability to trigger USB Type-C ACPI events, typically through physical USB device insertion or hardware manipulation. No public exploit code is referenced.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 1c5abcb13491da8c049f20462189c12c753ba978, 7dd27aed9c456670b3882877ef17a48195f21693, 7ef0423e43f877a328454059d46763043ce3da44, a6adfe9bbd6ac11e398b54ccd99a0f8eea09f3c0, f87fb985452ab2083967103ac00bfd68fb182764
Vendor Advisory: https://git.kernel.org/stable/c/1c5abcb13491da8c049f20462189c12c753ba978
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load patched kernel.
🔧 Temporary Workarounds
Disable UCSI support
linuxRemove or disable UCSI driver/module to prevent vulnerability trigger
echo 'blacklist ucsi' >> /etc/modprobe.d/blacklist-ucsi.conf
rmmod ucsi
🧯 If You Can't Patch
- Restrict physical access to USB ports on critical systems
- Monitor system logs for kernel panic events related to UCSI or USB Type-C
🔍 How to Verify
Check if Vulnerable:
Check if UCSI module is loaded: lsmod | grep ucsi. If loaded and kernel version predates fix commits, system may be vulnerable.Check Version:
uname -rVerify Fix Applied:
Check kernel version includes fix commits: uname -r and verify against distribution's patched kernel versions.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages mentioning ucsi_connector_change
- NULL pointer dereference errors in dmesg or kernel logs
- System crash/reboot events after USB device insertion
Network Indicators:
- None - this is a local kernel vulnerability
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "ucsi" OR "kernel panic")🔗 References
- https://git.kernel.org/stable/c/1c5abcb13491da8c049f20462189c12c753ba978
- https://git.kernel.org/stable/c/7dd27aed9c456670b3882877ef17a48195f21693
- https://git.kernel.org/stable/c/7ef0423e43f877a328454059d46763043ce3da44
- https://git.kernel.org/stable/c/a6adfe9bbd6ac11e398b54ccd99a0f8eea09f3c0
- https://git.kernel.org/stable/c/f87fb985452ab2083967103ac00bfd68fb182764
