CVE-2022-20022 in MT6580
Summary
by MITRE • 01/04/2022
In Bluetooth, there is a possible link disconnection due to bluetooth does not properly handle a connection attempt from a host with the same BD address as the currently connected BT host. This could lead to remote denial of service of bluetooth with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS06198578; Issue ID: ALPS06198578.
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Analysis
by VulDB Data Team • 01/06/2022
This vulnerability exists within the Bluetooth protocol implementation where a device fails to properly manage connection attempts from hosts sharing the same Bluetooth Device Address BDADDR. The flaw occurs during the connection establishment phase when the system does not adequately validate or handle duplicate BDADDR scenarios, creating a potential denial of service condition. The vulnerability specifically affects Bluetooth implementations that do not properly enforce connection state management when encountering identical device addresses, leading to unexpected disconnection behavior.
The technical root cause stems from insufficient input validation and connection state handling within the Bluetooth stack. When a new connection attempt is made using a BDADDR that matches an already connected device, the system fails to properly distinguish between legitimate connection retries and malicious attempts. This improper handling results in the current connection being terminated unexpectedly, effectively creating a remote denial of service condition. The vulnerability is classified under CWE-248 as an "Uncaught Exception" where the system does not properly handle exceptional conditions during connection management, and it aligns with ATT&CK technique T1499.001 for Network Denial of Service.
The operational impact of this vulnerability is significant as it allows remote attackers to disrupt Bluetooth connections without requiring any privileges or user interaction. The attack is particularly concerning because it can be executed from a remote location without the need for physical access or authentication. Once exploited, the vulnerability can cause persistent disconnections affecting Bluetooth functionality for the affected device. This could be particularly problematic in IoT devices, automotive systems, or any Bluetooth-enabled infrastructure where continuous connectivity is critical for operation. The vulnerability affects all Bluetooth implementations that do not properly handle duplicate BDADDR scenarios.
Mitigation strategies should focus on implementing proper connection state validation and handling mechanisms within Bluetooth stacks. Device manufacturers should ensure that their Bluetooth implementations properly validate connection attempts and maintain distinct connection states even when identical BDADDR values are encountered. The patch ALPS06198578 addresses this issue by enhancing the Bluetooth connection management logic to properly handle duplicate address scenarios without terminating existing connections. Organizations should also consider implementing network segmentation and monitoring for unusual disconnection patterns. Additionally, regular firmware updates and security assessments of Bluetooth implementations are crucial to prevent exploitation of similar connection management vulnerabilities. The fix should include enhanced error handling and proper state machine management to prevent the system from incorrectly interpreting duplicate BDADDR attempts as connection failures requiring termination of existing sessions.