CVE-2025-47827: Critical Security Vulnerability in IGEL OS allows Secure Boot Bypass

Overview

In the constantly evolving world of cybersecurity, new vulnerabilities are discovered almost every day. One such vulnerability, identified as CVE-2025-47827, has been found in IGEL OS versions before 11. This vulnerability is significant because it allows an attacker to bypass Secure Boot, a critical security feature designed to ensure that a system boots using only software that is trusted by the Original Equipment Manufacturer (OEM). The exploitation of this vulnerability could lead to potential system compromise or data leakage.
The vulnerability was discovered in IGEL OS, a power-packed, small and very secure Linux distribution that is widely used in thin clients, which makes it a high-risk issue. The fact that it can allow the mounting of a crafted root filesystem from an unverified SquashFS image underscores the severity of this threat.

Vulnerability Summary

CVE ID: CVE-2025-47827
Severity: High (8.4 CVSS Score)
Attack Vector: Local
Privileges Required: High
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

IGEL OS | Before Version 11

How the Exploit Works

The vulnerability resides in the igel-flash-driver module of the IGEL OS. This module is responsible for verifying the cryptographic signature of the boot files. However, due to an error in the verification process, an attacker with high-level privileges can bypass the Secure Boot process.
The attacker can craft a malicious root filesystem and mount it from an unverified SquashFS image. This allows the attacker to load untrusted code at system boot time, bypassing the integrity checks and leading to a potential system compromise.

Conceptual Example Code

Below is a conceptual example of how this vulnerability might be exploited using a shell command:

# Create a malicious SquashFS image
mksquashfs malicious_root_fs malicious.sqsh
# Mount the malicious image at boot time
echo "/dev/sda1 / squashfs defaults 0 0" >> /etc/fstab

In this example, `malicious_root_fs` is a directory containing the malicious root filesystem, and `malicious.sqsh` is the SquashFS image created from it. The second command mounts this image at boot time, effectively bypassing the Secure Boot process and loading untrusted code into the system.

Recommended Mitigation

Users are advised to apply the patch provided by the vendor as soon as possible. If the vendor patch is not yet available or cannot be applied immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation strategy to detect and block attempted exploits of this vulnerability.