Critical Linux kernel vulnerabilities (CVE-2024-27407, CVE-2024-57996, CVE-2025-37752, CVE-2025-38350) patched in Ubuntu 22.04 LTS. Learn about the security risks, affected AWS/GCP FIPS systems, and step-by-step update instructions to protect your servers from compromise.
Is your Ubuntu 22.04 LTS server secure? A recent security advisory from Canonical, designated USN-7726-3, addresses multiple critical-severity flaws within the Linux kernel that could allow a remote attacker to gain root privileges and fully compromise your system.
For DevOps engineers, system administrators, and cloud security professionals, this isn't just a routine update—it's an urgent patch for actively exploitable vulnerabilities affecting key subsystems.
This comprehensive analysis breaks down the threats, their impact on FIPS-compliant environments, and provides a clear remediation path to ensure your infrastructure remains secure and compliant.
Understanding the Security Threats: A Breakdown of the CVEs
The USN-7726-3 advisory patches several specific Common Vulnerabilities and Exposures (CVEs). Each CVE represents a unique weakness that attackers could chain together for a devastating breach. Understanding the nature of these flaws is the first step in appreciating the update's critical importance.
CVE-2024-27407 & CVE-2024-57996: These vulnerabilities reside within the kernel's Network Traffic Control (traffic control) subsystem. This component is responsible for managing packet scheduling, shaping, and policing. A flaw here could lead to a denial-of-service (DoS) condition, crashing the system, or potentially allowing for arbitrary code execution, giving an attacker control over the machine's networking stack.
CVE-2025-37752 & CVE-2025-38350: These weaknesses are found in the NTFS3 file system driver, the modern kernel module for reading and writing NTFS partitions. A local attacker could exploit these to corrupt kernel memory, escalate their privileges to root level, or bypass critical security boundaries, accessing sensitive data they shouldn't be able to.
Why are these vulnerabilities so dangerous? The combination of network-facing and local privilege escalation flaws is a potent mix.
An attacker could first use a traffic control vulnerability to gain a foothold on a system and then use an NTFS3 flaw to break out of containment and achieve full root access. This attack chain underscores the critical need for a defense-in-depth strategy, where every layer of the software stack is promptly patched.
Affected Systems: Are Your Ubuntu FIPS deployments at Risk?
This security update specifically targets Ubuntu deployments where Federal Information Processing Standards (FIPS) compliance is mandatory. FIPS is a set of U.S. government security requirements for cryptographic modules, often required in highly regulated industries like finance, healthcare, and government contracting.
The affected packages are niche but critical for secure cloud operations:
linux-aws-fips: The Linux kernel tailored for Amazon Web Services (AWS) environments requiring FIPS validation.linux-gcp-fips: The kernel module optimized for Google Cloud Platform (GCP) systems operating under FIPS mode.linux-fips: The generic FIPS-compliant kernel for on-premises or other cloud deployments.
If your organization operates in a regulated environment or leverages these specific kernel packages, your systems are exposed until this patch is applied. The widespread adoption of cloud infrastructure makes this a Tier 1 security concern for a large segment of enterprise users.
Step-by-Step Update Instructions: Securing Your Kernel
Patching these Linux kernel vulnerabilities is a straightforward process, but it requires a system reboot and awareness of a potential compatibility hurdle. Delaying this update leaves your servers vulnerable to known exploit vectors.
Here is the precise command sequence to apply the patch:
Update Your Package List: First, fetch the latest package information from Ubuntu's security repositories.
sudo apt-get update
Initiate the Upgrade: This command will download and install the new, patched kernel packages listed in the advisory.
sudo apt-get upgrade
Reboot Your System: A reboot is absolutely necessary to load the new, secure kernel into memory.
sudo reboot
Critical Attention Required: ABI Change and Third-Party Modules
This kernel update includes an Application Binary Interface (ABI) change, meaning the kernel's internal structures have shifted.
If you use any third-party kernel modules (e.g., proprietary drivers for graphics, VPNs, or custom hardware), you must recompile and reinstall them against the new kernel version after the update.
Most users relying on standard Ubuntu meta-packages (like linux-generic) will have this handled automatically. However, if you've installed custom drivers, consult the vendor's documentation for recompilation steps.
The Bigger Picture: The Critical Role of Kernel Security in DevOps
This incident highlights a core tenet of modern DevSecOps: proactive vulnerability management. The Linux kernel is the foundation of your entire software stack.
A vulnerability within it threatens every application and service running on top. For teams practicing Infrastructure as Code (IaC), this reinforces the need to integrate automated security patching into CI/CD pipelines.
Tools like Canonical's Livepatch can mitigate the need for immediate reboots for certain updates, though it's crucial to verify compatibility with critical security patches like this one.
Regularly monitoring sources like the Ubuntu Security Notice (USN) feed or subscribing to Common Vulnerability and Exposures (CVE) alerts is not just best practice—it's essential for maintaining a strong security posture in a landscape of sophisticated cyber threats.
Frequently Asked Questions (FAQ)
Q: Do I need to update if I'm not using FIPS?
A: The USN-7726-3 advisory specifically addresses the FIPS kernel variants. However, the same vulnerabilities were likely patched in the standard kernel packages under a different USN (e.g., USN-7726-1 or USN-7726-2). You should always apply all available security updates for your specific kernel flavor.
Q: What is the real-world risk of these CVEs?
A: While no public exploits are confirmed at the time of this writing, the nature of the flaws—especially those in the networking stack—makes them prime candidates for weaponization. Treat this update with high urgency.
Q: I use Ubuntu Pro. Does that help?
A: Yes. Ubuntu Pro subscribers benefit from an expanded security maintenance commitment, covering these kernels for a full ten years. It also provides access to the Ubuntu Livepatch service, which allows you to apply critical kernel fixes without rebooting, significantly reducing maintenance downtime.
Q: Where can I find the official security notices?
A: Always refer to the primary sources for the most accurate information:
Conclusion: The USN-7726-3 update is a mandatory security intervention for administrators of Ubuntu 22.04 LTS systems, particularly those in FIPS-compliant AWS or GCP environments. The patched vulnerabilities in the NTFS3 driver and network traffic control subsystem represent a tangible risk of system compromise.
By following the outlined update procedures and understanding the implications of the kernel ABI change, you can swiftly mitigate these threats and maintain the integrity and compliance of your mission-critical infrastructure.
Protect your systems: schedule this update immediately.
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