CVE-2025-21046 in Samsung
Summary
by MITRE • 10/10/2025
Improper access control in WindowManager in Samsung DeX prior to SMR Oct-2025 Release 1 allows physical attackers to temporarily access to recent app list.
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Analysis
by VulDB Data Team • 10/12/2025
The vulnerability identified as CVE-2025-21046 represents a critical access control flaw within Samsung DeX's WindowManager component that affects devices prior to the SMR October 2025 security release. This issue specifically targets the DeX environment which allows users to transform their Samsung smartphones into desktop-like experiences when connected to external displays. The vulnerability arises from insufficient validation mechanisms that govern how the system handles recent application access requests, creating a window of opportunity for unauthorized access to sensitive user data.
The technical flaw manifests in the improper handling of access control permissions within the WindowManager subsystem responsible for managing the display and interaction of applications in the DeX environment. When a device is connected to an external display and operating in DeX mode, the system's access control mechanisms fail to properly authenticate or authorize requests for accessing the recent applications list. This weakness allows an attacker with physical access to the device to temporarily retrieve information about recently used applications, potentially exposing sensitive data such as personal communications, financial applications, or confidential business information that was previously accessed by the user.
The operational impact of this vulnerability extends beyond simple data exposure, as it can enable attackers to gather intelligence about user behavior patterns and application usage habits. The temporary nature of the access means that the attacker can only retrieve this information during the specific window when the vulnerability is active, but this window can be sufficient to extract meaningful data about user activities, preferences, and potentially identify targets for further attacks. The vulnerability particularly affects users who rely on DeX for productivity work, as it could expose sensitive business applications and data that were recently accessed through the desktop environment.
Physical attackers can exploit this vulnerability by simply connecting to an active DeX session on a vulnerable device and leveraging the access control bypass to view the recent applications list. This attack vector is particularly concerning because it requires no network connectivity or complex exploitation techniques, relying instead on the attacker's physical proximity to the device. The vulnerability aligns with CWE-284 which addresses improper access control, and could potentially map to ATT&CK technique T1056.001 for input injection, as the attacker may be able to inject commands or requests that bypass normal access controls. The attack surface is further expanded when considering that many users leave their devices in DeX mode while working, creating extended windows of opportunity for exploitation.
Organizations and users should immediately apply the SMR October 2025 security update to address this vulnerability. System administrators should implement additional physical security controls for devices running DeX, including securing workstations and limiting unauthorized physical access to devices. Users should be educated about the risks of leaving devices in DeX mode unattended and should be encouraged to lock their devices or switch to secure screens when not actively using the desktop environment. The vulnerability highlights the importance of proper access control implementation in mobile operating system components and serves as a reminder that even seemingly minor access control flaws can have significant implications for user privacy and data security.