CVE-2024-50195 – A missing input validation vulnerability in the... (How to Fix)

Q: What is the severity of CVE-2024-50195?

CVE-2024-50195 has a CVSS score of 5.5 (MEDIUM). A missing input validation vulnerability in the Linux kernel's posix-clock subsystem allows attackers to pass invalid timespec64 values to PTP clock drivers. This affects systems using PTP (Precision Time Protocol) functionality with vulnerable drivers that lack their own validation. The vulnerability could lead to kernel instability or driver-specific issues.

📋 TL;DR

A missing input validation vulnerability in the Linux kernel's posix-clock subsystem allows attackers to pass invalid timespec64 values to PTP clock drivers. This affects systems using PTP (Precision Time Protocol) functionality with vulnerable drivers that lack their own validation. The vulnerability could lead to kernel instability or driver-specific issues.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE; typically affects multiple stable kernel versions before the fix commits.

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires PTP functionality to be enabled and used; systems without PTP clocks or drivers are not 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...

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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 →

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 or system crash due to invalid register writes in PTP drivers, potentially causing denial of service.

🟠

Likely Case

System instability or unexpected behavior in PTP time synchronization, possibly affecting time-sensitive applications.

🟢

If Mitigated

Minimal impact with proper input validation at higher layers or disabled PTP functionality.

🌐 Internet-Facing: LOW - Requires local access or specialized PTP network access; not directly exploitable over standard internet protocols.

🏢 Internal Only: MEDIUM - Local attackers or compromised processes could trigger the vulnerability, affecting system stability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM - Requires local access and ability to call clock_settime() with invalid parameters.

Exploitation depends on specific PTP driver implementations; some drivers may handle invalid inputs gracefully.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 1ff7247101af, 27abbde44b6e, 29f085345cde, 673a1c5a2998, a3f169e39821

Vendor Advisory: https://git.kernel.org/stable/c/1ff7247101af723731ea42ed565d54fb8f341264

Restart Required: Yes

Instructions:

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

🔧 Temporary Workarounds

Disable PTP functionality

linux

Prevent use of vulnerable PTP clock drivers by disabling PTP support.

echo 'blacklist ptp' >> /etc/modprobe.d/blacklist-ptp.conf
update-initramfs -u
reboot

🧯 If You Can't Patch

Restrict access to clock_settime() system call using seccomp or SELinux/AppArmor policies
Monitor for abnormal PTP driver behavior or kernel panics related to time setting operations

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if PTP modules are loaded: lsmod | grep ptp

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits: grep -r 'timespec64_valid_strict' /usr/src/linux-source-*/kernel/time/posix-clock.c

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
PTP driver error messages in dmesg
Invalid parameter warnings in system logs

Network Indicators:

Abnormal PTP protocol traffic patterns

SIEM Query:

source="kernel" AND ("panic" OR "oops" OR "EINVAL") AND ("ptp" OR "clock_settime")

📊 Metadata

CVE ID: CVE-2024-50195

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-754

Published: November 8, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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