CVE-2022-25809 in Echo Dot (AvA)
Summary
by MITRE • 02/24/2022
Improper Neutralization of audio output from 3rd and 4th Generation Amazon Echo Dot devices allows arbitrary voice command execution on these devices via a malicious skill (in the case of remote attackers) or by pairing a malicious Bluetooth device (in the case of physically proximate attackers), aka an "Alexa versus Alexa (AvA)" attack.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/26/2022
The vulnerability identified as CVE-2022-25809 represents a critical security flaw in Amazon Echo Dot devices spanning third and fourth generation models, where improper neutralization of audio output creates a pathway for unauthorized voice command execution. This vulnerability operates through two distinct attack vectors that exploit the device's audio processing capabilities and wireless communication protocols. The first vector involves remote attackers leveraging malicious Alexa skills to execute arbitrary commands, while the second vector targets physically proximate attackers who can pair malicious Bluetooth devices to achieve similar unauthorized control. This dual attack surface significantly expands the threat landscape for affected devices, as both remote and local adversaries can potentially exploit the flaw without requiring physical access to the device's internal components.
The technical root cause of this vulnerability lies in the insufficient sanitization of audio output streams generated by third-party Alexa skills or Bluetooth devices. When these audio sources are processed by the Echo Dot's voice recognition system, the device fails to properly validate or neutralize potentially malicious audio content that could be interpreted as voice commands. This weakness creates a scenario where audio signals containing encoded commands can be executed by the device's voice assistant without proper authentication or authorization checks. The flaw specifically affects the audio processing pipeline that handles external audio inputs, allowing malicious actors to inject commands that bypass normal security controls. According to CWE classification, this vulnerability maps to CWE-20: Improper Input Validation, as the system fails to properly validate audio inputs from external sources. The issue demonstrates characteristics of CWE-77: Command Injection, where external audio content can be interpreted as executable commands within the device's processing environment.
The operational impact of CVE-2022-25809 extends beyond simple unauthorized command execution to encompass potential privacy violations, device compromise, and unauthorized access to connected smart home ecosystems. An attacker who successfully exploits this vulnerability could potentially issue commands to control smart home devices, access personal information, or even use the device as a pivot point for further attacks within a network. The remote attack vector through malicious Alexa skills means that users could be compromised without their knowledge, as the malicious skill could be distributed through legitimate channels or masquerade as legitimate applications. The proximity-based Bluetooth attack vector adds another layer of concern, as it requires only physical access to the device to establish the malicious connection. This vulnerability particularly affects the ATT&CK framework's technique T1059.001 - Command and Scripting Interpreter, where adversaries can execute commands through legitimate system interfaces. The attack could also map to T1190 - Exploit Public-Facing Application, as the vulnerability exists in the device's exposed interfaces for third-party skill integration.
Mitigation strategies for CVE-2022-25809 require a multi-layered approach that addresses both the immediate vulnerability and broader security posture of affected devices. Organizations and individuals should immediately disable or remove any untrusted Alexa skills from their Echo devices and implement strict access controls for skill installations. The recommended approach includes regularly reviewing installed skills, disabling unused applications, and ensuring that only verified and trusted sources are granted access to the device's voice processing capabilities. Additionally, network segmentation should be implemented to limit the potential impact of a successful exploitation, and Bluetooth functionality should be disabled when not required for legitimate use cases. Security monitoring should include detection of unusual audio patterns or command execution attempts that could indicate exploitation attempts. Device firmware updates from Amazon should be applied promptly to address the underlying audio processing validation flaws, and users should maintain awareness of suspicious skill installations or Bluetooth pairing requests that could indicate malicious activity. The vulnerability highlights the importance of secure input validation in IoT devices and demonstrates the need for robust security controls in voice-activated systems that process external audio inputs.