CVE-2023-52846 – This CVE describes a use-after-free vulnerabili... (How to Fix)

Q: What is the severity of CVE-2023-52846?

CVE-2023-52846 has a CVSS score of 7.8 (HIGH). This CVE describes a use-after-free vulnerability in the Linux kernel's HSR/PRP network protocol implementation. An attacker could exploit this to cause a kernel crash (denial of service) or potentially execute arbitrary code with kernel privileges. Systems running vulnerable Linux kernel versions with HSR/PRP protocol enabled are affected.

📋 TL;DR

This CVE describes a use-after-free vulnerability in the Linux kernel's HSR/PRP network protocol implementation. An attacker could exploit this to cause a kernel crash (denial of service) or potentially execute arbitrary code with kernel privileges. Systems running vulnerable Linux kernel versions with HSR/PRP protocol enabled are affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific vulnerable kernel versions referenced in the git commits (need to check which kernel releases contain these commits)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if HSR/PRP protocol is enabled (CONFIG_HSR=y). This is typically not enabled in standard desktop/server distributions.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, or potential arbitrary code execution with kernel privileges resulting in complete system compromise.

🟠

Likely Case

Kernel crash causing system instability or denial of service, requiring system reboot to restore functionality.

🟢

If Mitigated

No impact if HSR/PRP protocol is disabled or system is patched.

🌐 Internet-Facing: LOW - HSR/PRP is typically used in industrial/embedded networks, not internet-facing systems.

🏢 Internal Only: MEDIUM - Affects industrial control systems, embedded devices, and specialized network equipment using HSR/PRP protocols.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires sending specially crafted network packets to systems with HSR/PRP enabled. No public exploits known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the referenced git commits: 1787b9f0729d318d67cf7c5a95f0c3dba9a7cc18, 6086258bd5ea7b5c706ff62da42b8e271b2401db, 876f8ab52363f649bcc74072157dfd7adfbabc0d, a1a485e45d24b1cd8fe834fd6f1b06e2903827da, d103fb6726904e353b4773188ee3d3acb4078363

Vendor Advisory: https://git.kernel.org/stable/c/1787b9f0729d318d67cf7c5a95f0c3dba9a7cc18

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable HSR/PRP protocol

linux

Disable the vulnerable kernel module if not required

echo "install hsr /bin/true" >> /etc/modprobe.d/disable-hsr.conf
rmmod hsr

Network segmentation

all

Isolate systems using HSR/PRP from untrusted networks

🧯 If You Can't Patch

Disable HSR/PRP protocol in kernel configuration and remove module
Implement strict network filtering to block HSR/PRP traffic from untrusted sources

🔍 How to Verify

Check if Vulnerable:

Check if HSR module is loaded: lsmod | grep hsr. Check kernel version against affected versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and HSR module version matches patched version if enabled.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
OOM killer activity
System crash/reboot logs

Network Indicators:

Unusual HSR/PRP protocol traffic patterns
Malformed network packets to HSR ports

SIEM Query:

source="kernel" AND ("panic" OR "Oops" OR "general protection fault") AND process="hsr"

📊 Metadata

CVE ID: CVE-2023-52846

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: May 21, 2024

Last Updated: December 31, 2024

🔗 References

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🔗 Related Vulnerabilities

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