CVE-2023-53464 – This CVE addresses a null pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2023-53464?

CVE-2023-53464 has a CVSS score of 5.5 (MEDIUM). This CVE addresses a null pointer dereference vulnerability in the Linux kernel's iSCSI TCP module. An attacker could potentially cause a kernel panic or system crash by triggering the vulnerability before the socket is properly initialized. Systems using iSCSI storage connections with affected kernel versions are at risk.

📋 TL;DR

This CVE addresses a null pointer dereference vulnerability in the Linux kernel's iSCSI TCP module. An attacker could potentially cause a kernel panic or system crash by triggering the vulnerability before the socket is properly initialized. Systems using iSCSI storage connections with affected kernel versions are at risk.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific kernel versions between the introduction of commit 57569c37f0ad and the fix commits listed in references

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when iSCSI TCP module is loaded and in use. Systems not using iSCSI storage 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...

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 →

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, potentially disrupting iSCSI storage connectivity and causing data unavailability.

🟠

Likely Case

System instability or crash when iSCSI connections are established under specific timing conditions, resulting in temporary service disruption.

🟢

If Mitigated

Minimal impact if systems are not using iSCSI storage connections or have proper kernel crash recovery mechanisms in place.

🌐 Internet-Facing: LOW - iSCSI typically runs on internal storage networks, not directly internet-exposed.

🏢 Internal Only: MEDIUM - Systems using iSCSI storage in data centers or enterprise environments could experience service disruption.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to trigger iSCSI connection establishment under specific timing conditions. No public exploits known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing fixes from the referenced commits (48b19b79cfa37b1e50da3b5a8af529f994c08901 and others)

Vendor Advisory: https://git.kernel.org/stable/c/48b19b79cfa37b1e50da3b5a8af529f994c08901

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify iSCSI connections function normally after reboot.

🔧 Temporary Workarounds

Disable iSCSI TCP module

linux

Prevent loading of vulnerable iSCSI TCP kernel module if iSCSI storage is not required

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

🧯 If You Can't Patch

Ensure iSCSI connections are only established from trusted network segments
Implement monitoring for kernel panics and system crashes related to iSCSI operations

🔍 How to Verify

Check if Vulnerable:

Check kernel version and verify if iSCSI TCP module is loaded: 'lsmod | grep iscsi_tcp' and 'uname -r'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated to patched version and iSCSI connections remain stable during connection establishment

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/messages or dmesg
iSCSI connection failures in system logs

Network Indicators:

Unexpected iSCSI connection resets or timeouts

SIEM Query:

source="kernel" AND ("panic" OR "Oops") AND "iscsi"

📊 Metadata

CVE ID: CVE-2023-53464

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: 0.02% exploit probability (5.5th percentile)

Published: October 1, 2025

Last Updated: January 20, 2026

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2023-53464, you might also want to check these: