Ubiquiti UniFi Devices Use of AES-CBC Allows Key Recovery and Unauthorized Device Control

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.

A malformed discovery packet sent by a malicious actor with preexisting access to the network could interrupt the functionality of device management and discovery. Affected Products: UniFi Access Points UniFi Switches UniFi LTE Backup UniFi Express (Only Mesh Mode, Router mode is not affected) Mitigation: Update UniFi Access Points to Version 6.6.55 or later. Update UniFi Switches to Version 6.6.61 or later. Update UniFi LTE Backup to Version 6.6.57 or later. Update UniFi Express to Version 3.2.5 or later.