CVE-2023-53458
📋 TL;DR
This CVE describes a null pointer dereference vulnerability in the Linux kernel's cx23885 media driver. When DMA memory allocation fails during buffer preparation, subsequent buffer operations can trigger kernel crashes or potential privilege escalation. Systems using affected kernel versions with the cx23885 driver loaded are vulnerable.
💻 Affected Systems
- Linux kernel with cx23885 media driver
📦 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 panic leading to system crash, or potential local privilege escalation to kernel mode if combined with other vulnerabilities.
Likely Case
System crash or instability when the driver fails to allocate memory, requiring reboot to restore functionality.
If Mitigated
Minor system instability that self-recovers or requires driver reload.
🎯 Exploit Status
Requires local access and ability to trigger specific driver operations. Similar to previously fixed vulnerability referenced in CVE description.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 47e8b73bc35d7c54642f78e498697692f6358996, 5b8e5e28e85a546dfccc3895befe0e823fdd7c89, 6738841f6fcf23e9fc30e2449f32fc84ee19c6f1, or f0a06203f2fe63f04311467200c99c4ee1926578
Vendor Advisory: https://git.kernel.org/stable/c/47e8b73bc35d7c54642f78e498697692f6358996
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify driver is no longer vulnerable.
🔧 Temporary Workarounds
Disable cx23885 driver
linuxPrevent loading of vulnerable driver module
echo 'blacklist cx23885' >> /etc/modprobe.d/blacklist-cx23885.conf
rmmod cx23885
🧯 If You Can't Patch
- Ensure cx23885 driver is not loaded (check with 'lsmod | grep cx23885')
- Restrict local user access to systems where driver must remain loaded
🔍 How to Verify
Check if Vulnerable:
Check if cx23885 driver is loaded: 'lsmod | grep cx23885'. If loaded, check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
After patching, verify driver still functions with media capture operations and system remains stable.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference in kernel logs
- cx23885 driver crash logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
kernel: "NULL pointer dereference" AND "cx23885" OR kernel: "BUG: unable to handle kernel NULL pointer"