CVE-2025-20700: Airoha Bluetooth SDK Privilege Escalation

CVE-2025-20700 Overview

CVE-2025-20700 is a permission bypass vulnerability in the Airoha Bluetooth audio Software Development Kit (SDK). The flaw allows an attacker within Bluetooth range to access critical data of the Remote Audio Control Enhancement (RACE) protocol through the Bluetooth Low Energy (BLE) Generic Attribute Profile (GATT) service. Exploitation requires no authentication and no user interaction. The vulnerability maps to CWE-306: Missing Authentication for Critical Function and impacts confidentiality, integrity, and availability of affected devices.

Critical Impact

An adjacent attacker can escalate privileges remotely on Airoha-based Bluetooth audio devices without authentication or user interaction.

Affected Products

• Airoha Bluetooth audio SDK
• Bluetooth audio devices built on Airoha chipsets implementing the RACE protocol
• Downstream OEM headsets, earbuds, and speakers integrating the vulnerable SDK

Discovery Timeline

• 2025-08-04 - CVE-2025-20700 published to the National Vulnerability Database (NVD)
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-20700

Vulnerability Analysis

The Airoha Bluetooth audio SDK exposes the RACE protocol over a BLE GATT service. RACE is a proprietary control channel used to configure, debug, and manage Airoha-based audio devices. The GATT service that handles RACE traffic does not enforce authentication or authorization before granting access to its characteristics. Any device within Bluetooth radio range can connect, read, and write RACE commands.

Because RACE provides privileged control over the device firmware, an attacker leveraging this exposed interface can issue commands that should be restricted to trusted, paired hosts. The CVSS vector indicates adjacent network access with high impact to confidentiality, integrity, and availability, reflecting the broad capability granted by the RACE channel once reached.

Root Cause

The root cause is missing authentication on a security-critical function, classified as [CWE-306]. The GATT characteristics that proxy RACE protocol commands lack access control checks. The SDK relies on the assumption that only paired peers will interact with these endpoints, but the GATT server accepts requests from any nearby BLE central.

Attack Vector

An attacker positioned within Bluetooth range scans for advertising Airoha-based audio devices. The attacker connects to the target as a BLE central and enumerates GATT services. After locating the RACE GATT characteristic, the attacker writes crafted RACE protocol frames to issue privileged commands. No pairing, bonding, or user prompt is required. The Airoha Product Security Bulletin provides additional vendor context, available at the Airoha Product Security Bulletin.

No verified public proof-of-concept code is available. The vulnerability mechanism is described in prose per the vendor advisory.

Detection Methods for CVE-2025-20700

Indicators of Compromise

• Unexpected BLE GATT connections to audio devices from unknown or unpaired centrals
• RACE protocol writes originating from devices outside the user's normal pairing history
• Firmware configuration changes, parameter resets, or unauthorized debug-mode activations on Airoha-based audio peripherals

Detection Strategies

• Capture BLE traffic with sniffers such as Ubertooth or Nordic nRF Sniffer near deployed audio devices and inspect for writes to RACE GATT characteristics from non-paired peers
• Audit mobile and host endpoint logs for Bluetooth connection events to audio peripherals that do not correspond to user-initiated pairings
• Correlate proximity-based anomalies with device behavior changes such as unexpected reboots or audio routing modifications

Monitoring Recommendations

• Maintain an inventory of Airoha-based Bluetooth audio devices and firmware versions across the environment
• Monitor vendor security bulletins for updated SDK and firmware releases addressing CVE-2025-20700
• Track Bluetooth host stack logs on managed endpoints for unusual GATT enumeration patterns targeting audio peripherals

How to Mitigate CVE-2025-20700

Immediate Actions Required

• Apply firmware updates from device OEMs that incorporate the patched Airoha Bluetooth audio SDK as soon as available
• Disable Bluetooth on affected devices when not in active use, particularly in untrusted physical environments
• Restrict use of vulnerable audio peripherals in sensitive areas where adjacent attackers could position within radio range

Patch Information

Refer to the Airoha Product Security Bulletin for the list of patched SDK versions and remediation guidance. Device-level patches must be distributed by the OEM that integrated the Airoha SDK. Contact the device manufacturer to obtain firmware that enforces authentication on the RACE GATT service.

Workarounds

• Keep affected devices unpaired and powered off when not in use to eliminate radio exposure
• Operate audio devices only in physically controlled environments that exclude untrusted BLE-capable devices within range
• Where supported by the OEM companion app, disable any developer or debug modes that expose extended RACE functionality

# Configuration example: disable Bluetooth on a Linux host managing audio peripherals
sudo rfkill block bluetooth
sudo systemctl stop bluetooth.service
sudo systemctl disable bluetooth.service