Ubuntu 24.04 LTS Azure Kernel Security Update: Critical Vulnerabilities Patched

Critical Linux kernel security vulnerabilities (CVE-2025-38001, CVE-2025-37798, CVE-2025-37932) patched in Ubuntu 24.04 LTS Azure. Learn how to update, reboot, and mitigate risks for enterprise cloud systems. Official fixes, update instructions, and expert analysis included.

Urgent Security Alert for Azure Cloud Users

Ubuntu has released a critical security patch (USN-7609-4) for the Linux kernel in Ubuntu 24.04 LTS deployments on Microsoft Azure. 

This update addresses 7 high-risk vulnerabilities (CVEs 2025-38001, 2025-37798, 2025-37932, and more) that could allow attackers to compromise cloud systems. Enterprises relying on Azure-hosted Ubuntu must act immediately.

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Affected Systems & Vulnerability Breakdown

Distro: Ubuntu 24.04 LTS
Package: linux-azure kernel
Severity: Critical (Remote Code Execution / Privilege Escalation risks)

Key Vulnerabilities Patched

1. InfiniBand Driver Flaws (CVE-2025-38001) – Memory corruption risks.

2. Netfilter Exploits (CVE-2025-37798) – Bypass firewall rules.

3. Network Traffic Control Bugs (CVE-2025-37932) – DoS attacks possible.

Why This Matters: Cloud environments are high-value targets. Unpatched kernels risk data breaches, service outages, and compliance violations.

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Step-by-Step Update Instructions

To secure your system:

1. Update Packages:

   bash

   sudo apt update && sudo apt upgrade linux-azure

2. Verify Kernel Version:
   Ensure you’re running:

   • linux-image-6.8.0-1031-azure 6.8.0-1031.36

   • (or FDE variants for encrypted systems).

3. Reboot: Mandatory for changes to take effect.

⚠️ ABI Change Warning: Third-party kernel modules require recompilation. Use:

bash

sudo apt install --reinstall [module-name]

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Mitigation & Best Practices

• Automate Updates: Use unattended-upgrades for critical patches.

• Monitor Logs: Check /var/log/kern.log for exploitation attempts.

• Network Segmentation: Limit InfiniBand and Netfilter exposure.

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FAQs

Q: Can I delay the reboot?

A: No—kernel updates require a reboot to mitigate active threats.

Q: Are containers affected?

A: Only if running privileged containers or host-level kernels.

Q: How to verify CVE fixes?

A: Cross-reference Ubuntu’s security notices.