CVE-2024-43873 – This CVE addresses an uninitialized variable vu... (How to Fix)

Q: What is the severity of CVE-2024-43873?

CVE-2024-43873 has a CVSS score of 7.8 (HIGH). This CVE addresses an uninitialized variable vulnerability in the Linux kernel's vhost/vsock subsystem. The seqpacket_allow variable is not properly initialized when a socket is created, potentially allowing attackers to read uninitialized kernel memory. This affects systems using vhost/vsock with the VIRTIO_VSOCK_F_SEQPACKET feature.

📋 TL;DR

This CVE addresses an uninitialized variable vulnerability in the Linux kernel's vhost/vsock subsystem. The seqpacket_allow variable is not properly initialized when a socket is created, potentially allowing attackers to read uninitialized kernel memory. This affects systems using vhost/vsock with the VIRTIO_VSOCK_F_SEQPACKET feature.

💻 Affected Systems

Products:

Linux kernel

Versions: Kernel versions with the vulnerable vhost/vsock code before the fix commits

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires vhost/vsock to be enabled and used with VIRTIO_VSOCK_F_SEQPACKET feature

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Information disclosure of kernel memory contents, potentially leading to kernel address space layout randomization (KASLR) bypass or exposure of sensitive data.

🟠

Likely Case

Information leak of kernel memory, which could be used to infer kernel addresses or other system information.

🟢

If Mitigated

Minimal impact if proper kernel hardening and memory protection mechanisms are in place.

🌐 Internet-Facing: LOW - vhost/vsock is typically used for host-guest communication in virtualization environments, not directly internet-facing.

🏢 Internal Only: MEDIUM - Affects virtualization hosts and containers using vsock for communication between host and guests.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires access to create vsock sockets and manipulate features

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the fix commits: 1e1fdcbdde3b7663e5d8faeb2245b9b151417d22, 3062cb100787a9ddf45de30004b962035cd497fb, 30bd4593669443ac58515e23557dc8cef70d8582, ea558f10fb05a6503c6e655a1b7d81fdf8e5924c, eab96e8716cbfc2834b54f71cc9501ad4eec963b

Vendor Advisory: https://git.kernel.org/stable/c/1e1fdcbdde3b7663e5d8faeb2245b9b151417d22

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.

🔧 Temporary Workarounds

Disable vhost/vsock

linux

Disable the vhost/vsock module if not required

echo 'blacklist vhost_vsock' > /etc/modprobe.d/disable-vhost-vsock.conf
rmmod vhost_vsock

🧯 If You Can't Patch

Disable vhost/vsock module if not required for system functionality
Implement strict access controls to limit who can create vsock sockets

🔍 How to Verify

Check if Vulnerable:

Check kernel version and verify if vhost/vsock is loaded: lsmod | grep vhost_vsock

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version contains one of the fix commits: uname -r

📡 Detection & Monitoring

Log Indicators:

Kernel oops or warnings related to vhost/vsock
Unexpected vsock socket creation

Network Indicators:

Unusual vsock communication patterns

SIEM Query:

process.name:vhost-vsock OR module:vhost_vsock

📊 Metadata

CVE ID: CVE-2024-43873

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-909

Published: August 21, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2024-43873, you might also want to check these: