What’s Vulnerable › Vulnerabilities

CVE-2019-25651: Ubiquiti UniFi Devices Use of AES-CBC Allows Key Recovery and Unauthorized Device Control

• Severity: high (CVSS 8.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-27 · updated 2026-06-17
• Weakness: CWE-327

Description

Ubiquiti UniFi Network Controller prior to 5.10.12 (excluding 5.6.42), UAP FW prior to 4.0.6, UAP-AC, UAP-AC v2, and UAP-AC Outdoor FW prior to 3.8.17, USW FW prior to 4.0.6, USG FW prior to 4.4.34 uses AES-CBC encryption for device-to-controller communication, which contains cryptographic weaknesses that allow attackers to recover encryption keys from captured traffic. Attackers with adjacent network access can capture sufficient encrypted traffic and exploit AES-CBC mode vulnerabilities to derive the encryption keys, enabling unauthorized control and management of network devices.

Affected products

• Ubiquiti UniFi Network Controller: before 5.6.42; from 5.6.43 before 5.10.12 — fixed in 5.10.12, 5.6.42
• Ubiquiti UniFi UAP-AC Firmware: before 3.8.17 — fixed in 3.8.17
• Ubiquiti UniFi UAP Firmware: before 4.0.6 — fixed in 4.0.6
• Ubiquiti UniFi USG Firmware: before 4.4.34 — fixed in 4.4.34
• Ubiquiti UniFi USW Firmware: before 4.0.6 — fixed in 4.0.6

How to fix

Upgrade to a fixed version: Ubiquiti UniFi Network Controller 5.10.12, 5.6.42; Ubiquiti UniFi UAP-AC Firmware 3.8.17; Ubiquiti UniFi UAP Firmware 4.0.6; Ubiquiti UniFi USG Firmware 4.4.34; Ubiquiti UniFi USW Firmware 4.0.6. Check the vendor advisory for mitigations.

References

• https://community.ui.com/releases/Security-Advisory-Bulletin-004-004/462e561b-9efd-4c23-bfa7-53d59cc64ecb
• https://www.vulncheck.com/advisories/ubiquiti-unifi-devices-use-of-aes-cbc-allows-key-recovery-and-unauthorized-device-control

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