CVE-2022-48851 – This is a use-after-free vulnerability in the L... (How to Fix)

Q: What is the severity of CVE-2022-48851?

CVE-2022-48851 has a CVSS score of 7.8 (HIGH). This is a use-after-free vulnerability in the Linux kernel's gdm724x staging driver. An attacker could exploit this to cause a kernel crash (denial of service) or potentially execute arbitrary code with kernel privileges. Systems using the vulnerable gdm724x LTE driver are affected.

📋 TL;DR

This is a use-after-free vulnerability in the Linux kernel's gdm724x staging driver. An attacker could exploit this to cause a kernel crash (denial of service) or potentially execute arbitrary code with kernel privileges. Systems using the vulnerable gdm724x LTE driver are affected.

💻 Affected Systems

Products:

Linux kernel with gdm724x staging driver

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

Operating Systems: Linux distributions with vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if the gdm724x staging driver is loaded. This is a staging driver not typically enabled by default in production systems.

📦 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, or potential arbitrary code execution with kernel privileges resulting in complete system compromise.

🟠

Likely Case

Kernel crash causing denial of service, requiring system reboot to recover.

🟢

If Mitigated

Limited impact if driver is not loaded or system has kernel hardening protections like KASLR and SMEP/SMAP enabled.

🌐 Internet-Facing: LOW - This requires local access or ability to trigger the vulnerable driver function.

🏢 Internal Only: MEDIUM - Local attackers or malicious users could exploit this to crash systems or potentially escalate privileges.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and ability to trigger the vulnerable gdm_lte_rx() function. No public exploits have been reported.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 1fb9dd3787495b4deb0efe66c58306b65691a48f, 403e3afe241b62401de1f8629c9c6b9b3d69dbff, 48ecdf3e29a6e514e8196691589c7dfc6c4ac169, 6d9700b445098dbbce0caff4b8cfca214cf1e757, 6dc7b87c62423bfa68139fe95e85028aab584c9a

Vendor Advisory: https://git.kernel.org/stable/c/1fb9dd3787495b4deb0efe66c58306b65691a48f

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Check with your distribution for specific patched kernel versions. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable gdm724x driver

linux

Prevent loading of the vulnerable staging driver

echo 'blacklist gdm724x' >> /etc/modprobe.d/blacklist.conf
rmmod gdm724x

🧯 If You Can't Patch

Ensure the gdm724x driver is not loaded (check with lsmod)
Implement strict access controls to prevent local users from triggering the vulnerable function

🔍 How to Verify

Check if Vulnerable:

Check if gdm724x module is loaded: lsmod | grep gdm724x. If loaded, check kernel version against patched versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated to include the fix commits and gdm724x module is either not loaded or updated.

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
System crash/reboot events
OOM killer or kernel oops messages

Network Indicators:

Unusual local network activity targeting LTE interfaces

SIEM Query:

EventID=41 OR Source='kernel' AND Message LIKE '%panic%' OR Message LIKE '%Oops%'

📊 Metadata

CVE ID: CVE-2022-48851

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-416

Published: July 16, 2024

Last Updated: November 21, 2024

🔗 References

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🔗 Related Vulnerabilities

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