CVE-2023-2008 – This vulnerability in the Linux kernel's udmabu... (How to Fix)

Q: What is the severity of CVE-2023-2008?

CVE-2023-2008 has a CVSS score of 7.8 (HIGH). This vulnerability in the Linux kernel's udmabuf driver allows local attackers to escalate privileges and execute arbitrary code with kernel permissions. It affects Linux systems with the udmabuf driver loaded. The flaw stems from improper validation of user-supplied data leading to out-of-bounds memory access.

📋 TL;DR

This vulnerability in the Linux kernel's udmabuf driver allows local attackers to escalate privileges and execute arbitrary code with kernel permissions. It affects Linux systems with the udmabuf driver loaded. The flaw stems from improper validation of user-supplied data leading to out-of-bounds memory access.

💻 Affected Systems

Products:

Linux kernel

Versions: Kernel versions before commit 05b252cccb2e5c3f56119d25de684b4f810ba4 (May 2023)

Operating Systems: Linux distributions with udmabuf driver enabled

Default Config Vulnerable: ✅ No

Notes: Requires udmabuf driver to be loaded (not loaded by default on most distributions). Systems using GPU virtualization or specific DMA buffer features are more likely affected.

📦 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 →

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

Full system compromise with root-level code execution, allowing attackers to install persistent malware, steal sensitive data, or disrupt system operations.

🟠

Likely Case

Local privilege escalation from unprivileged user to root, enabling attackers to bypass security controls and access restricted resources.

🟢

If Mitigated

Limited impact with proper access controls, SELinux/AppArmor policies, and minimal user privileges reducing attack surface.

🌐 Internet-Facing: LOW

🏢 Internal Only: HIGH

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and ability to interact with udmabuf device. Proof-of-concept code is publicly available in security advisories.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions including commit 05b252cccb2e5c3f56119d25de684b4f810ba4

Vendor Advisory: https://bugzilla.redhat.com/show_bug.cgi?id=2186862

Restart Required: Yes

Instructions:

1. Update kernel package using distribution's package manager. 2. For RHEL/CentOS: 'yum update kernel'. 3. For Ubuntu/Debian: 'apt update && apt upgrade linux-image-*'. 4. Reboot system to load patched kernel.

🔧 Temporary Workarounds

Disable udmabuf module

linux

Prevent loading of vulnerable udmabuf driver module

echo 'blacklist udmabuf' >> /etc/modprobe.d/blacklist-udmabuf.conf
rmmod udmabuf

Restrict device access

linux

Limit access to udmabuf device nodes

chmod 600 /dev/udmabuf*
setfacl -m u:root:rw /dev/udmabuf*

🧯 If You Can't Patch

Implement strict access controls to prevent unauthorized users from accessing system
Use SELinux/AppArmor to restrict kernel module loading and device access

🔍 How to Verify

Check if Vulnerable:

Check if udmabuf module is loaded: 'lsmod | grep udmabuf'. Check kernel version: 'uname -r'. Compare with patched versions from vendor advisories.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched version. Confirm udmabuf module functions correctly if required for system operation.

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages related to udmabuf
Failed privilege escalation attempts in audit logs
Unexpected kernel module loading

Network Indicators:

None - local exploitation only

SIEM Query:

source="kernel" AND "udmabuf" OR source="audit" AND type="AVC" AND scontext="kernel"

📊 Metadata

CVE ID: CVE-2023-2008

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-129

Published: April 14, 2023

Last Updated: May 5, 2025

🔗 References

https://bugzilla.redhat.com/show_bug.cgi?id=2186862 Issue Tracking,Patch,Third Party Advisory
https://github.com/torvalds/linux/commit/05b252cccb2e5c3f56119d25de684b4f810ba4 Patch
https://security.netapp.com/advisory/ntap-20230517-0007/ Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-23-441/ Third Party Advisory,VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=2186862 Issue Tracking,Patch,Third Party Advisory
https://github.com/torvalds/linux/commit/05b252cccb2e5c3f56119d25de684b4f810ba4 Patch
https://security.netapp.com/advisory/ntap-20230517-0007/ Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-23-441/ Third Party Advisory,VDB Entry

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2023-2008, you might also want to check these: