Critical Ubiquiti Vulnerability Puts Your Business Doors at Risk: CVE-2025-27212 Explained

On July 16, 2025, Ubiquiti Networks issued a crucial safety alert that should alarm any business owner who uses UniFi Access control systems. The vulnerability, CVE-2025-27212, has a maximum CVSS score of 9.8, making it one of the most severe physical security threats we've observed this year.

If your business uses UniFi door readers, access controls, or intercoms, this flaw could allow attackers to completely compromise your building security.

Here's what you need to know and do immediately.

A Perfect Storm for Attackers

CVE-2025-27212 received the maximum 9.8 CVSS score because it combines the worst criteria of a security vulnerability. Bongeun Koo and Junhyung Cho, security researchers, determined that improper input validation in UniFi Access devices allows for command injection attacks.

What Makes This Vulnerability So Dangerous

Remote Network Exploitation (AV:N) - Attackers can exploit this remotely over the network without physical access to your devices.

No Authentication Required (PR:N) - The most concerning aspect: criminals don't need usernames, passwords, or any credentials to exploit this vulnerability.

Low Attack Complexity (AC:L) - Basic knowledge of command injection is sufficient. No specialized conditions or tools required.

Complete System Impact - Successful exploitation provides high impact to confidentiality, integrity, and availability (C:H/I:H/A:H).

The CVSS vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H tells the story: this vulnerability can be exploited by anyone with network access to your UniFi management systems, and the impact is total system compromise.

How The Attack Works

Attackers create malicious input that the UniFi Access system fails to validate. This allows them to "inject" operating-system commands into valid queries. For example, what should be a simple device configuration request transforms into a gateway to execute any command on the underlying system.

Why UniFi Access Systems Are Prime Targets

UniFi Access has become incredibly popular with small and medium businesses because of its affordability and ease of use. Starting at $499 for a starter kit, these systems can scale to support up to 20,000 users while integrating seamlessly with existing UniFi network equipment.

The affected devices include:

// UniFi Access Reader Pro (≤2.14.21)

// UniFi Access G2 Reader Pro (≤1.10.32)

// UniFi Access G3 Reader Pro (≤1.10.30)

// UniFi Access Intercom (≤1.7.28)

// UniFi Access G3 Intercom (≤1.7.29)

// UniFi Access Intercom Viewer (≤1.3.20)

What attackers can accomplish:

// Unlock any door connected to compromised systems

// Manipulate access logs to hide their presence

// Create new access credentials for future unauthorized entry

// Disable integrated security cameras

// Install malware for ongoing surveillance

// Conduct network reconnaissance from inside your security perimeter

Unlike normal network security breaches, physical access control compromises pose immediate concerns such as illegal building entry during off-hours, theft of equipment and confidential documents, personal safety risks for personnel, and potential liability issues if client data is physically accessed.

Immediate Actions Required

1. Identify Your Risk

Check your UniFi Access devices immediately. Log into your UniFi controller and verify the firmware versions of all Access devices. Any device running the vulnerable versions listed above needs immediate attention.

2. Update Firmware Immediately

Ubiquiti has released security patches for all affected products:

// UniFi Access Reader Pro: Update to version 2.15.9 or later

// UniFi Access G2 Reader Pro: Update to version 1.11.23 or later

// UniFi Access G3 Reader Pro: Update to version 1.11.22 or later

// UniFi Access Intercom: Update to version 1.8.22 or later

// UniFi Access G3 Intercom: Update to version 1.8.22 or later

// UniFi Access Intercom Viewer: Update to version 1.4.39 or later

3. Network Isolation

As a temporary mitigation measure, isolate your Access management networks from your main corporate network. This limits an attacker's ability to move laterally if a device is compromised.

4. Review and Monitor

Check recent access logs for any unusual activity or entries you can't explain. Implement monitoring for unusual command execution patterns if possible.

Why Professional Management Matters

This vulnerability exposes a major issue that many firms face: they build security solutions but fail to maintain them adequately. The most typical issues are delayed security updates, poor network segmentation, insufficient monitoring of access patterns, and a lack of cybersecurity experience among employees.

CVE-2025-27212 serves as a wake-up call about the convergence of physical and digital security. As businesses increasingly rely on networked access control systems, the traditional boundaries between IT security and physical security are disappearing.

The sophistication of modern threats requires a professional approach to security management. Businesses that try to handle complex security systems in-house often miss critical updates, fail to properly configure network segmentation, and lack the expertise to respond effectively to incidents.

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Contact Ghost Systems Inc. for a comprehensive security assessment that covers both your digital networks and physical access systems.