CVE-2025-21073 is a vulnerability identified in Samsung Mobile devices related to an insecure default configuration of the USB connection mode prior to the SMR (Security Maintenance Release) November 2025 Release 1. The root cause is classified under CWE-1188, which pertains to the initialization of a resource with insecure default settings. In this case, the USB connection mode is configured in a way that allows privileged physical attackers—those with direct physical access to the device—to potentially access user data without proper authorization. The vulnerability requires user interaction to be triggered, meaning the user must perform some action such as accepting a prompt or connecting the device in a certain mode. The CVSS v3.1 score is 6.8, indicating a medium severity level. The vector string (AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) shows that the attack requires adjacent network access (physically connecting via USB), high attack complexity, no privileges required, no user interaction, unchanged scope, and results in high confidentiality and integrity impact but no availability impact. No known exploits have been reported in the wild, and no official patches are linked yet, though the vulnerability is addressed in the SMR Nov-2025 Release 1. This vulnerability poses a risk primarily to users who may connect their devices to untrusted USB hosts or allow physical access to attackers. The insecure default USB mode could expose sensitive data stored on the device or compromise data integrity. The threat is particularly relevant for environments where mobile devices are used to store or access sensitive corporate or personal information. Given the physical access requirement and user interaction, remote exploitation is not feasible, but insider threats or theft scenarios are plausible attack vectors.

For European organizations, this vulnerability could lead to unauthorized access to sensitive user data on Samsung Mobile devices if attackers gain physical access and the user interacts with the device to trigger the exploit. This could result in data breaches, loss of confidentiality, and potential integrity compromises of critical information stored on mobile devices. Industries with high mobile device usage for sensitive communications, such as finance, healthcare, and government sectors, are at increased risk. The inability to remotely exploit the vulnerability limits widespread automated attacks but raises concerns about insider threats, device theft, or loss scenarios. The impact on availability is negligible, but the confidentiality and integrity impacts are high, potentially leading to regulatory compliance issues under GDPR if personal data is exposed. Organizations relying heavily on Samsung Mobile devices should consider this vulnerability in their mobile device management and physical security policies. The lack of an immediate patch means that mitigation must focus on access control and user awareness until the official SMR update is deployed.

1. Deploy the SMR November 2025 Release 1 or later security updates as soon as they become available to ensure the insecure default USB connection mode is corrected. 2. Enforce strict physical security controls to prevent unauthorized physical access to mobile devices, including secure storage and device tracking. 3. Implement mobile device management (MDM) solutions that can restrict USB connection modes or disable USB data transfer capabilities when devices are connected to untrusted hosts. 4. Educate users about the risks of connecting their devices to unknown or untrusted USB hosts and the importance of not accepting unexpected prompts related to USB connections. 5. Use endpoint encryption and strong authentication mechanisms to protect data on devices, reducing the impact if physical access is gained. 6. Monitor device logs and USB connection events for unusual activity that could indicate attempted exploitation. 7. Consider disabling USB debugging and developer modes on devices where not required, as these can increase attack surface. 8. For high-risk environments, consider deploying hardware-based security modules or secure elements that limit data exposure even if USB access is compromised.