CVE-2022-48732 – This CVE describes an off-by-one buffer boundar... (How to Fix)

Q: What is the severity of CVE-2022-48732?

CVE-2022-48732 has a CVSS score of 7.8 (HIGH). This CVE describes an off-by-one buffer boundary checking vulnerability in the Nouveau DRM driver in the Linux kernel. When parsing BIOS initialization scripts, the driver incorrectly rejects access to the last valid byte, causing driver initialization failures. This primarily affects systems with specific NVIDIA GeForce 2 MX GPUs on OpenFirmware machines like PowerPC Macs, potentially leaving systems without a working console.

📋 TL;DR

This CVE describes an off-by-one buffer boundary checking vulnerability in the Nouveau DRM driver in the Linux kernel. When parsing BIOS initialization scripts, the driver incorrectly rejects access to the last valid byte, causing driver initialization failures. This primarily affects systems with specific NVIDIA GeForce 2 MX GPUs on OpenFirmware machines like PowerPC Macs, potentially leaving systems without a working console.

💻 Affected Systems

Products:

Linux kernel with Nouveau DRM driver

Versions: Linux kernel versions before the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Primarily affects systems with NVIDIA GeForce 2 MX GPUs on OpenFirmware/PowerPC systems like Apple eMacs. Most x86 systems are unaffected due to different BIOS handling.

📦 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

Complete system instability or denial of service during boot, leaving the system without a functional console or display output, requiring physical access to recover.

🟠

Likely Case

Driver initialization failure during boot on affected hardware, resulting in no display output and system becoming unusable until kernel is patched or hardware is replaced.

🟢

If Mitigated

No impact on properly patched systems or systems without the specific affected hardware configuration.

🌐 Internet-Facing: LOW - This is a local driver initialization issue, not remotely exploitable over networks.

🏢 Internal Only: MEDIUM - Affects system availability during boot on specific hardware, but requires physical or local access to trigger.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: LOW - Triggered automatically during driver initialization on affected hardware

This is a denial of service condition triggered during system boot with specific hardware, not a traditional security exploit for privilege escalation or remote access.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel versions containing the fix commits (1b777d4d9e383d2744fc9b3a09af6ec1893c8b1a and related)

Vendor Advisory: https://git.kernel.org/stable/c/1b777d4d9e383d2744fc9b3a09af6ec1893c8b1a

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable Nouveau driver

linux

Prevent Nouveau driver from loading during boot

Add 'nouveau.modeset=0' to kernel boot parameters in GRUB configuration

Use proprietary NVIDIA driver

linux

Replace Nouveau with NVIDIA's proprietary driver

Install NVIDIA proprietary driver package for your distribution

🧯 If You Can't Patch

Replace affected hardware (GeForce 2 MX GPU) with different GPU
Use different system without PowerPC/OpenFirmware architecture

🔍 How to Verify

Check if Vulnerable:

Check if system has GeForce 2 MX GPU and uses Nouveau driver: lspci | grep -i nvidia && lsmod | grep nouveau

Check Version:

uname -r

Verify Fix Applied:

Check kernel version contains fix: uname -r and verify against distribution's patched kernel versions

📡 Detection & Monitoring

Log Indicators:

Kernel logs showing Nouveau driver initialization failures
dmesg | grep -i nouveau errors during boot

Network Indicators:

None - local issue only

SIEM Query:

source="kernel" AND "nouveau" AND ("error" OR "failed" OR "panic")

📊 Metadata

CVE ID: CVE-2022-48732

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-193

Published: June 20, 2024

Last Updated: November 21, 2024

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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