CVE-2025-38693 – This CVE describes a null pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2025-38693?

CVE-2025-38693 has a CVSS score of 5.5 (MEDIUM). This CVE describes a null pointer dereference vulnerability in the Linux kernel's w7090p DVB frontend driver. Attackers with local access can trigger a kernel crash (denial of service) by sending specially crafted messages to the vulnerable driver. Systems using Linux kernels with the affected driver are vulnerable.

📋 TL;DR

This CVE describes a null pointer dereference vulnerability in the Linux kernel's w7090p DVB frontend driver. Attackers with local access can trigger a kernel crash (denial of service) by sending specially crafted messages to the vulnerable driver. Systems using Linux kernels with the affected driver are vulnerable.

💻 Affected Systems

Products:

Linux kernel with w7090p DVB frontend driver

Versions: Kernel versions containing the vulnerable driver code before the fix commits

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only systems with w7090p DVB hardware or driver loaded are vulnerable. Most servers won't have this driver active by default.

📦 What is this software?

Debian Linux by Debian

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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...

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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...

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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

Local privilege escalation leading to full system compromise if combined with other vulnerabilities, or kernel panic causing system crash and data loss.

🟠

Likely Case

Local denial of service through kernel crash/panic, requiring system reboot to recover.

🟢

If Mitigated

Minimal impact if proper access controls prevent untrusted users from accessing DVB devices.

🌐 Internet-Facing: LOW - Requires local access to the system; not directly exploitable over network.

🏢 Internal Only: MEDIUM - Local users or compromised accounts could crash the kernel, affecting system availability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and knowledge of driver interaction. Similar to CVE-2023-31081 pattern.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions with commits 17b30e5ded062bd74f8ca6f317e1d415a8680665 or later

Vendor Advisory: https://git.kernel.org/stable/c/17b30e5ded062bd74f8ca6f317e1d415a8680665

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from distribution vendor. 2. Rebuild kernel if using custom build. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable w7090p driver module

Linux

Prevent loading of vulnerable driver if not needed

echo 'blacklist w7090p' >> /etc/modprobe.d/blacklist.conf
rmmod w7090p

🧯 If You Can't Patch

Restrict access to DVB devices using file permissions (chmod 600 /dev/dvb/*)
Implement mandatory access control (SELinux/AppArmor) to limit driver interactions

🔍 How to Verify

Check if Vulnerable:

Check if w7090p module is loaded: lsmod | grep w7090p. If loaded and kernel version is unpatched, system is vulnerable.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commit: grep -q '17b30e5ded062bd74f8ca6f317e1d415a8680665' /proc/version_signature || uname -r shows patched version.

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages in /var/log/kern.log
System crash/panic logs
Failed DVB device operations

Network Indicators:

None - local exploit only

SIEM Query:

source="kern.log" AND "Oops" AND "w7090p" OR source="kern.log" AND "general protection fault"

📊 Metadata

CVE ID: CVE-2025-38693

CVSS v3 Score: 5.5 (MEDIUM)

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

CWE: CWE-476

EPSS Score: 0.01% exploit probability (2.3th percentile)

Published: September 4, 2025

Last Updated: January 9, 2026

🔗 References

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