CVE-2019-16336 in PSoC 4
Summary
by MITRE
The Bluetooth Low Energy implementation in Cypress PSoC 4 BLE component 3.61 and earlier processes data channel frames with a payload length larger than the configured link layer maximum RX payload size, which allows attackers (in radio range) to cause a denial of service (crash) via a crafted BLE Link Layer frame.
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Analysis
by VulDB Data Team • 03/30/2024
The vulnerability CVE-2019-16336 affects the Bluetooth Low Energy implementation within Cypress PSoC 4 BLE components version 3.61 and earlier, representing a critical flaw in embedded wireless communication systems. This issue resides in the link layer processing mechanism where the system fails to properly validate incoming data channel frames against configured maximum receive payload sizes. The flaw specifically manifests when an attacker within radio range transmits a crafted BLE Link Layer frame containing payload data that exceeds the established maximum RX payload limits. This vulnerability falls under the CWE-129 weakness category, which encompasses issues related to improper validation of input boundaries and buffer overflows in wireless communication protocols.
The technical exploitation of this vulnerability occurs through the improper handling of frame processing within the Bluetooth Low Energy stack of the PSoC 4 BLE component. When the system receives a frame with oversized payload data, it lacks proper bounds checking mechanisms to validate whether the incoming data conforms to the configured link layer maximum RX payload size. The implementation fails to reject or properly process frames that exceed these boundaries, leading to unpredictable behavior and system instability. This type of vulnerability represents a classic buffer overflow condition within wireless communication protocols, where the system attempts to process data beyond its allocated memory boundaries. The ATT&CK framework categorizes this under the T1489 technique for "Service Stop" as the exploitation results in denial of service conditions that can crash the affected system.
The operational impact of this vulnerability extends beyond simple system crashes, as it provides attackers with a reliable method to disrupt wireless communication services within radio range of the affected devices. The denial of service condition can render Bluetooth Low Energy communication capabilities completely non-functional, affecting any device or application that relies on the PSoC 4 BLE component for wireless connectivity. This represents a significant security concern for IoT devices, wearables, and embedded systems where continuous wireless communication is critical for proper operation. The vulnerability's accessibility through radio range means that physical proximity to the target device is sufficient for exploitation, making it particularly dangerous in environments where unauthorized physical access is possible. The affected systems may experience complete loss of wireless functionality until manual intervention or power cycling occurs, potentially leading to extended service interruptions in mission-critical applications.
Mitigation strategies for this vulnerability should focus on immediate firmware updates to versions 3.62 or later where the proper bounds checking mechanisms have been implemented. System administrators should conduct comprehensive inventory assessments to identify all affected PSoC 4 BLE components within their network infrastructure and prioritize remediation efforts accordingly. Network segmentation and physical security measures should be enhanced to prevent unauthorized access to vulnerable devices in the interim period before full patching is achieved. Additionally, implementing monitoring solutions that can detect anomalous BLE traffic patterns may help identify exploitation attempts before they cause significant service disruption. Organizations should also consider implementing redundant communication pathways or alternative wireless technologies to maintain operational continuity during the remediation process, particularly in environments where wireless connectivity is essential for system operation and safety.