CVE-2025-44557 is a vulnerability identified in the Bluetooth Low Energy (BLE) stack of Cypress PSoC4 microcontrollers, specifically version 3.66. The flaw arises from a state machine transition error within the BLE protocol implementation. This error allows an attacker to bypass the standard pairing and authentication processes by sending a specially crafted 'pairing_failed' packet. Normally, the BLE pairing process ensures that only authorized devices can establish a secure connection, protecting data confidentiality and device integrity. However, due to this vulnerability, an attacker can circumvent these security checks, potentially gaining unauthorized access to the device or its data without completing the legitimate pairing procedure. The vulnerability is rooted in the BLE stack's handling of state transitions during pairing, which fails to correctly validate or respond to unexpected or malformed packets, leading to an authentication bypass. Although no known exploits have been reported in the wild yet, the flaw's nature suggests that it could be exploited by attackers within radio range to compromise affected devices. The lack of a CVSS score indicates that the vulnerability is newly published and may not yet have undergone full impact assessment. The affected product, Cypress PSoC4, is a widely used family of microcontrollers in embedded systems, IoT devices, and consumer electronics, which rely on BLE for wireless communication. This vulnerability could thus have broad implications for devices using this chipset and BLE stack version 3.66.

For European organizations, the impact of this vulnerability could be significant, especially for those deploying IoT devices, industrial control systems, or consumer electronics that incorporate Cypress PSoC4 microcontrollers with BLE capabilities. Unauthorized bypass of BLE pairing and authentication can lead to unauthorized device access, data interception, or manipulation, potentially compromising sensitive information or operational integrity. In industrial or critical infrastructure contexts, this could disrupt processes or enable lateral movement within networks. Consumer devices affected could expose personal data or allow attackers to use devices as entry points into home or corporate networks. The wireless nature of BLE means that attackers do not require physical access, only proximity, increasing the risk in densely populated or public environments common in European urban centers. Additionally, the lack of a patch or mitigation at the time of publication means organizations may remain exposed until Cypress releases a firmware update or alternative remediation.

Given the absence of an official patch or update, European organizations should implement layered mitigations. First, conduct an inventory to identify devices using Cypress PSoC4 BLE stack version 3.66. Where possible, disable BLE functionality on devices that do not require it or restrict BLE usage to trusted environments. Employ physical security controls to limit attacker proximity to vulnerable devices, such as shielding or controlled access areas. Monitor BLE traffic for anomalous pairing attempts or malformed packets indicative of exploitation attempts. Network segmentation can limit the impact of compromised devices. Engage with Cypress and device vendors to obtain firmware updates or security advisories and plan timely deployment of patches once available. Additionally, consider deploying BLE security gateways or intrusion detection systems capable of filtering or alerting on suspicious BLE activity. For new deployments, evaluate alternative hardware or BLE stacks with proven security track records until this vulnerability is resolved.