CVE-2025-21018 is a medium-severity vulnerability classified as an out-of-bounds read (CWE-125) affecting Samsung Mobile's Blockchain Keystore component prior to version 1.3.17.2. This vulnerability allows a local attacker with privileged access to read memory beyond the intended bounds. Specifically, the flaw arises from improper bounds checking when accessing memory buffers, which can lead to the disclosure of sensitive information stored in adjacent memory regions. Since the vulnerability requires local privileged access, it cannot be exploited remotely or by unprivileged users. The vulnerability does not impact system integrity or availability but compromises confidentiality by potentially exposing sensitive cryptographic keys or other protected data managed by the Blockchain Keystore. The CVSS 3.1 base score is 4.4, reflecting a medium severity level, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), high privileges required (PR:H), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), and no impact on integrity or availability (I:N/A:N). No known exploits are currently reported in the wild, and no patches or updates have been linked yet. The vulnerability was reserved in November 2024 and published in August 2025. The Blockchain Keystore is a critical component for managing cryptographic keys related to blockchain applications on Samsung mobile devices, making the confidentiality impact significant for users relying on this technology for secure transactions or identity management.

For European organizations, the impact of CVE-2025-21018 depends largely on the deployment of Samsung mobile devices utilizing the vulnerable Blockchain Keystore. Organizations involved in blockchain-based financial services, identity verification, or secure mobile transactions could face confidentiality risks if attackers gain local privileged access to devices. This could lead to exposure of cryptographic keys, potentially enabling unauthorized access to blockchain wallets or digital assets. Although exploitation requires local privileged access, insider threats or malware that escalates privileges could leverage this vulnerability to extract sensitive data. The impact on operational continuity is minimal since the vulnerability does not affect integrity or availability. However, the confidentiality breach could undermine trust in mobile blockchain solutions and result in regulatory compliance issues under GDPR if personal or financial data is exposed. The threat is more pronounced in sectors with high mobile device usage for blockchain applications, such as fintech, banking, and government digital identity programs in Europe.

To mitigate CVE-2025-21018, European organizations should prioritize updating Samsung mobile devices to Blockchain Keystore version 1.3.17.2 or later once patches are released by Samsung. Until patches are available, organizations should enforce strict access controls to prevent unauthorized local privileged access, including robust endpoint protection, privilege management, and monitoring for suspicious privilege escalation activities. Employ mobile device management (MDM) solutions to enforce security policies and restrict installation of untrusted applications that could facilitate privilege escalation. Additionally, organizations should conduct regular security audits and penetration testing focused on privilege escalation vectors on mobile devices. For critical blockchain applications, consider additional encryption layers or hardware security modules (HSMs) to protect keys beyond the Blockchain Keystore. User education on the risks of rooting or jailbreaking devices, which can increase exposure to local attacks, is also essential.