CVE-2025-20971 is a medium-severity vulnerability identified in Samsung Flow, a software product developed by Samsung Mobile that facilitates seamless data and content transfer between Samsung mobile devices and PCs. The vulnerability stems from improper input validation (CWE-20) in versions prior to 4.9.17.6 of Samsung Flow. Specifically, local attackers with limited privileges (PR:L) can exploit this flaw without requiring user interaction (UI:N) to gain unauthorized access to data managed by Samsung Flow. The CVSS 3.1 base score of 5.5 reflects a moderate risk, with a high impact on confidentiality (C:H), but no impact on integrity (I:N) or availability (A:N). The attack vector is local (AV:L), meaning the attacker must have local access to the device, and the attack complexity is low (AC:L), indicating no special conditions are needed beyond local access. The vulnerability does not require user interaction, which increases the likelihood of exploitation once local access is obtained. Although no known exploits are currently reported in the wild, the flaw could allow malicious insiders or attackers who have gained local access to extract sensitive data from Samsung Flow, potentially exposing personal or corporate information synchronized between devices. The absence of a patch link suggests that remediation may be pending or that users should upgrade to version 4.9.17.6 or later once available. This vulnerability highlights the critical importance of robust input validation in software that handles sensitive data synchronization across devices.

For European organizations, this vulnerability poses a moderate risk primarily to confidentiality. Samsung Flow is widely used in corporate environments to facilitate productivity by enabling seamless data transfer between mobile devices and PCs. Unauthorized local access to Samsung Flow data could lead to exposure of sensitive corporate documents, personal data, or intellectual property. This risk is particularly relevant for organizations with bring-your-own-device (BYOD) policies or those that rely heavily on Samsung mobile devices integrated with desktop environments. Although the attack requires local access, insider threats or attackers who gain physical or remote local access (e.g., through compromised endpoints) could exploit this vulnerability to extract confidential information. This could result in data breaches, regulatory non-compliance (e.g., GDPR violations), and reputational damage. The lack of impact on integrity and availability reduces the risk of data manipulation or service disruption but does not diminish the confidentiality concerns. Organizations in sectors such as finance, healthcare, and government, where data confidentiality is paramount, may face heightened risks.

European organizations should implement the following specific mitigation measures: 1) Ensure all Samsung Flow installations are updated to version 4.9.17.6 or later as soon as the patch is available to address the input validation flaw. 2) Enforce strict local access controls on devices running Samsung Flow, including strong authentication mechanisms and endpoint security solutions to prevent unauthorized local access. 3) Monitor and audit local device access logs to detect suspicious activity indicative of insider threats or unauthorized physical access. 4) Limit the use of Samsung Flow on devices handling highly sensitive data or restrict its use to managed corporate devices with hardened security configurations. 5) Educate employees about the risks of local device compromise and the importance of securing their devices, especially in BYOD scenarios. 6) Employ endpoint detection and response (EDR) tools to identify and respond to potential exploitation attempts. 7) Review and update data synchronization policies to minimize sensitive data exposure through Samsung Flow where possible.