CVE-2023-53032 – This CVE describes an integer overflow vulnerab... (How to Fix)

Q: What is the severity of CVE-2023-53032?

CVE-2023-53032 has a CVSS score of 5.5 (MEDIUM). This CVE describes an integer overflow vulnerability in the Linux kernel's netfilter ipset module. When creating bitmap IP sets with specific parameters (first_ip=0, last_ip=0xFFFFFFFF, netmask=31), an arithmetic expression can overflow before being widened to a larger data type. The vulnerability affects Linux systems using the ipset functionality.

📋 TL;DR

This CVE describes an integer overflow vulnerability in the Linux kernel's netfilter ipset module. When creating bitmap IP sets with specific parameters (first_ip=0, last_ip=0xFFFFFFFF, netmask=31), an arithmetic expression can overflow before being widened to a larger data type. The vulnerability affects Linux systems using the ipset functionality.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected kernel versions not specified in CVE, but patches exist in stable kernel trees

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when using netfilter ipset functionality with specific parameters (first_ip=0, last_ip=0xFFFFFFFF, netmask=31)

📦 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

Potential kernel panic or denial of service leading to system instability or crash, though the overflowed value is checked at the next step which limits the impact.

🟠

Likely Case

System instability or kernel panic when creating specific ipset configurations, resulting in denial of service for affected systems.

🟢

If Mitigated

No impact if the vulnerable code path isn't triggered through ipset configuration.

🌐 Internet-Facing: LOW - Requires local access or ability to configure ipset rules, typically not directly exposed to internet.

🏢 Internal Only: MEDIUM - Could be exploited by users with sufficient privileges to configure ipset rules, potentially causing system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to create ipset configurations with specific parameters, typically requiring root or CAP_NET_ADMIN privileges.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in stable kernel versions via provided git commits

Vendor Advisory: https://git.kernel.org/stable/c/4e6a70fd840400e3a2e784a6673968a3eb2431c0

Restart Required: Yes

Instructions:

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

🔧 Temporary Workarounds

Disable ipset module

linux

Prevent loading of vulnerable netfilter ipset module

echo 'blacklist ip_set' > /etc/modprobe.d/blacklist-ipset.conf
rmmod ip_set

Restrict ipset configuration

linux

Limit users who can configure ipset rules

chmod 750 /sbin/ipset
setcap -r /sbin/ipset

🧯 If You Can't Patch

Restrict access to ipset configuration tools to trusted administrators only
Monitor system logs for ipset configuration attempts and kernel panic events

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare with patched versions from distribution vendor. Vulnerable if using unpatched kernel with ipset functionality.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version matches patched version from vendor and test ipset creation with vulnerable parameters.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
System crash/reboot events
ipset configuration logs with specific parameters

Network Indicators:

Unexpected system reboots affecting network services

SIEM Query:

source="kernel" AND ("panic" OR "Oops") OR source="auth" AND program="ipset"

📊 Metadata

CVE ID: CVE-2023-53032

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-190

EPSS Score: 0.05% exploit probability (15.4th percentile)

Published: March 27, 2025

Last Updated: October 31, 2025

🔗 References

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