CVE-2025-21036 is a medium-severity vulnerability identified in Samsung Notes, a widely used note-taking application on Samsung mobile devices. The vulnerability stems from improper access control related to the use of implicit intents for sensitive communication within the application. Specifically, prior to version 4.4.30.63, Samsung Notes improperly exposes exported note files to local privileged attackers. This means that an attacker with some level of local privilege on the device can exploit this flaw to access sensitive note files that should otherwise be protected. The vulnerability requires user interaction to be triggered, indicating that the attacker must convince or trick the user into performing an action that initiates the exploit. The CVSS 3.1 base score is 5.0, reflecting a medium severity level, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and no availability impact (A:N). The underlying weakness is categorized under CWE-927, which relates to the use of implicit intents for sensitive communication, a common Android security issue where intents are not explicitly targeted, potentially allowing unauthorized apps or processes to intercept or access sensitive data. No known exploits have been reported in the wild, and no patch links are provided in the data, but the issue is addressed in Samsung Notes version 4.4.30.63 and later. This vulnerability primarily affects Samsung mobile devices running vulnerable versions of Samsung Notes, exposing sensitive user data to local attackers who have gained some level of device access, such as through other privilege escalation vulnerabilities or physical access.

For European organizations, the impact of this vulnerability can be significant, especially for those whose employees use Samsung mobile devices for work-related note-taking and data storage. The exposure of sensitive notes could lead to unauthorized disclosure of confidential business information, intellectual property, or personal data, potentially violating GDPR requirements regarding data protection and privacy. Since the vulnerability requires local privileged access and user interaction, the risk is somewhat mitigated but still relevant in scenarios where devices are lost, stolen, or compromised by malware that gains local privileges. The confidentiality impact is high, as sensitive notes can be accessed without integrity or availability being affected. This could facilitate corporate espionage, data leaks, or insider threats. Organizations in sectors such as finance, healthcare, legal, and government, where sensitive information is frequently stored on mobile devices, are particularly at risk. Additionally, the lack of known exploits in the wild suggests that proactive patching and mitigation can effectively prevent exploitation. However, the widespread use of Samsung devices in Europe means that a large number of endpoints could be vulnerable if not updated promptly.

1. Immediate update of Samsung Notes to version 4.4.30.63 or later on all Samsung mobile devices used within the organization to ensure the vulnerability is patched. 2. Implement mobile device management (MDM) solutions to enforce application updates and control app permissions, limiting the ability of unauthorized apps to gain local privileges or intercept intents. 3. Educate users about the risks of interacting with suspicious prompts or links that could trigger the vulnerability, emphasizing cautious behavior regarding app interactions and downloads. 4. Restrict local privilege escalation by enforcing strong device security policies, including secure lock screens, biometric authentication, and disabling developer options or USB debugging on corporate devices. 5. Monitor device logs and behavior for signs of privilege escalation or unusual access patterns to note files, enabling early detection of exploitation attempts. 6. Consider encrypting sensitive notes or using alternative secure note-taking applications with stronger access controls for highly sensitive information. 7. Regularly audit and review installed applications and permissions on corporate mobile devices to minimize the attack surface.