CVE-2025-21064 is a vulnerability classified under CWE-287 (Improper Authentication) affecting Samsung Mobile's Smart Switch software versions prior to 3.7.66.6. Smart Switch is a utility used to transfer data between Samsung mobile devices and other platforms. The flaw allows an adjacent attacker—someone within the same local network or physical proximity—to bypass authentication controls and access data being transferred. The vulnerability does not require any privileges or user interaction, making it easier to exploit in environments where devices communicate over Wi-Fi or other local connections. The CVSS 3.1 base score of 8.8 reflects the critical impact on confidentiality, integrity, and availability, as the attacker can intercept, modify, or disrupt data transfers. Although no exploits are currently known in the wild, the vulnerability's characteristics suggest a high risk of exploitation once publicized. The lack of patch links indicates that a fix may be pending or not yet widely distributed. This vulnerability poses a significant risk to users transferring sensitive or proprietary information via Smart Switch, especially in enterprise or government contexts where data leakage or tampering could have severe consequences.

For European organizations, the impact of CVE-2025-21064 can be substantial. Many enterprises and public sector entities use Samsung devices and Smart Switch for data migration and synchronization. An attacker positioned on the same local network—such as in corporate offices, public Wi-Fi hotspots, or shared facilities—could intercept sensitive personal or corporate data during transfer. This could lead to data breaches, intellectual property theft, or disruption of critical communications. The integrity of transferred data could be compromised, resulting in corrupted or maliciously altered information. Availability could also be affected if attackers disrupt or block data transfers. Given the high CVSS score and the lack of required authentication or user interaction, the threat is particularly acute in environments with dense device usage and shared network access. European organizations handling sensitive personal data under GDPR may face regulatory and reputational consequences if such data is exposed or manipulated.

To mitigate this vulnerability effectively, European organizations should: 1) Immediately inventory and identify all Samsung devices using Smart Switch, especially versions prior to 3.7.66.6. 2) Apply the official patch or update Smart Switch to version 3.7.66.6 or later as soon as it becomes available from Samsung. 3) Restrict local network access during data transfers by segmenting networks and using secure Wi-Fi configurations with strong encryption and authentication. 4) Educate users to avoid transferring sensitive data over untrusted or public networks and to verify device connections before initiating transfers. 5) Employ network monitoring tools to detect unusual local traffic patterns indicative of man-in-the-middle or eavesdropping attempts. 6) Consider temporary alternative secure data transfer methods until the vulnerability is patched. 7) Implement endpoint security controls to detect and prevent unauthorized access to mobile devices. These measures go beyond generic advice by focusing on network segmentation, user awareness, and proactive monitoring tailored to the nature of this adjacent attacker threat.