CVE-2023-0775 in Gecko SDK
Summary
by MITRE • 03/28/2023
An invalid ‘prepare write request’ command can cause the Bluetooth LE stack to run out of memory and fail to be able to handle subsequent connection requests, resulting in a denial-of-service.
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Analysis
by VulDB Data Team • 03/28/2023
The vulnerability identified as CVE-2023-0775 represents a critical denial-of-service weakness within Bluetooth Low Energy stack implementations that stems from improper handling of prepare write requests. This flaw specifically targets the Bluetooth 5.0 specification and its associated GATT (Generic Attribute Profile) protocol stack, where the system fails to adequately validate incoming prepare write requests. The issue manifests when a malicious actor or faulty device sends malformed prepare write commands that exploit memory management gaps in the Bluetooth LE implementation, leading to uncontrolled memory consumption.
The technical root cause of this vulnerability lies in the insufficient input validation mechanisms within the Bluetooth LE stack's GATT server component. When a prepare write request is received, the system should validate the request parameters and ensure proper memory allocation for the pending write operations. However, in affected implementations, the stack does not properly check the integrity of the prepare write request structure, allowing attackers to send requests with malformed data or excessive payload sizes that cause the memory allocator to consume resources without proper cleanup. This memory exhaustion condition specifically affects the GATT server's ability to maintain concurrent connections and process new incoming requests.
From an operational perspective, this vulnerability creates a severe disruption to Bluetooth LE services and can be exploited by adversaries to render Bluetooth devices completely non-functional. The impact extends beyond simple service interruption as the memory exhaustion causes the Bluetooth stack to become unresponsive to legitimate connection attempts, effectively creating a persistent denial-of-service condition. Network infrastructure relying on Bluetooth LE for device communication, such as IoT sensors, smart home systems, industrial monitoring equipment, and mobile device peripherals, could experience complete service outages. The vulnerability is particularly concerning in environments where continuous connectivity is critical, as the denial-of-service condition can persist until the device is manually rebooted or the Bluetooth stack is reset.
The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and can be mapped to ATT&CK technique T1499.001 for network denial-of-service attacks. The exploitation requires minimal privileges and can be performed remotely through Bluetooth LE connections, making it particularly dangerous in environments where Bluetooth devices are frequently accessed by untrusted parties. Security professionals should implement immediate mitigations including firmware updates from device manufacturers, network segmentation to limit Bluetooth access, and monitoring for unusual prepare write request patterns. Additionally, implementing rate limiting on GATT operations and memory watchdog mechanisms can help detect and prevent exploitation attempts, while regular system health monitoring should be established to identify potential memory exhaustion conditions before they result in complete service disruption.