CVE-2025-21027 is a vulnerability identified in Samsung Mobile Devices affecting the ImsService component prior to the September 2025 Security Maintenance Release (SMR). The root cause is an improper verification of intent by a broadcast receiver, classified under CWE-925 (Improper Verification of Intent). Broadcast receivers in Android listen for system-wide or application-specific intents to trigger actions. In this case, the ImsService's broadcast receiver does not adequately verify the authenticity or intent of incoming broadcasts, allowing a local attacker to send crafted intents that can temporarily disable the SIM card functionality. This vulnerability requires local access to the device, meaning the attacker must have some level of access to execute code or send intents locally without user interaction or elevated privileges. The CVSS v3.1 score is 5.1 (medium severity), reflecting that while the attack vector is local and no privileges or user interaction are needed, the impact is limited to availability (temporary SIM disablement) without affecting confidentiality or integrity. There are no known exploits in the wild, and no patches have been linked yet, indicating this is a recently disclosed vulnerability. The temporary SIM disablement could disrupt cellular connectivity, affecting calls, SMS, and data services until the device or service is restored. The vulnerability is specific to Samsung Mobile Devices, which are widely used globally, including Europe.

For European organizations, the impact of CVE-2025-21027 primarily concerns availability of mobile communication services on Samsung devices. Organizations relying on Samsung smartphones for critical communications, two-factor authentication (2FA) via SMS, or mobile data connectivity could experience temporary disruptions if devices are targeted locally by malicious actors. While the vulnerability does not compromise data confidentiality or integrity, the temporary SIM disablement could hinder business operations, emergency communications, or access to mobile network-dependent applications. This is particularly relevant for sectors with high reliance on mobile connectivity such as finance, healthcare, and emergency services. Additionally, the requirement for local access limits remote exploitation risks but raises concerns in environments where devices may be physically accessible to attackers, such as shared workspaces or public areas. The lack of known exploits reduces immediate risk, but organizations should remain vigilant given the potential for targeted attacks or insider threats.

To mitigate CVE-2025-21027, European organizations should: 1) Ensure all Samsung Mobile Devices are updated promptly with the latest SMR patches once available from Samsung, as the vulnerability is fixed in the September 2025 release. 2) Implement strict physical security controls to prevent unauthorized local access to devices, including secure storage and device management policies. 3) Employ Mobile Device Management (MDM) solutions to monitor device health and connectivity status, enabling rapid detection of SIM disablement or unusual behavior. 4) Educate users about the risks of installing untrusted applications or granting permissions that could facilitate local exploitation. 5) For critical communications, consider multi-channel redundancy (e.g., Wi-Fi calling, alternative devices) to maintain availability during potential SIM disruptions. 6) Monitor vendor advisories and security bulletins for updates or patches related to this vulnerability. These steps go beyond generic advice by focusing on physical security, device management, and operational continuity specific to the nature of this local attack vector.