CVE-2025-21017 is a security vulnerability classified as an out-of-bounds write (CWE-787) found in the Samsung Mobile Blockchain Keystore component prior to version 1.3.17.2. The flaw occurs specifically during the detachment of a crypto box, where a local attacker with privileged access can write data beyond the intended memory boundaries. This type of memory corruption can lead to unpredictable behavior, including corruption of adjacent memory, potential escalation of privileges, or execution of arbitrary code. The vulnerability requires local access with high privileges (PR:H), no user interaction (UI:N), and has a low attack complexity (AC:L). The CVSS v3.1 base score is 6.3, indicating a medium severity level. The impact vector includes high confidentiality and integrity impacts, with a low availability impact. No known exploits are currently reported in the wild, and no patches or mitigation links are provided in the source data. Since the vulnerability affects the Blockchain Keystore, a component likely used for secure cryptographic key storage and operations on Samsung mobile devices, exploitation could compromise sensitive cryptographic material, potentially undermining the security of blockchain-related applications or secure transactions on affected devices. The vulnerability is local and requires privileged access, which limits remote exploitation but still poses a significant risk if an attacker gains elevated privileges on the device.

For European organizations, especially those relying on Samsung mobile devices for secure blockchain transactions, digital identity management, or cryptographic key storage, this vulnerability could lead to serious security breaches. Compromise of the Blockchain Keystore could allow attackers to extract or manipulate cryptographic keys, leading to unauthorized transactions, data tampering, or identity theft. Organizations in sectors such as finance, telecommunications, and government that use Samsung devices for secure mobile operations could face confidentiality and integrity breaches. Although exploitation requires local privileged access, insider threats or malware that escalates privileges could leverage this vulnerability to deepen compromise. The medium severity score suggests a moderate but non-trivial risk, emphasizing the need for timely patching and monitoring. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

European organizations should prioritize updating Samsung Blockchain Keystore to version 1.3.17.2 or later as soon as it becomes available to address this vulnerability. Until patches are released, organizations should enforce strict access controls on mobile devices to prevent unauthorized privilege escalation. Implement mobile device management (MDM) solutions to monitor and restrict installation of untrusted applications and detect privilege escalation attempts. Regularly audit device security settings and user privileges to minimize the risk of local privilege abuse. Additionally, organizations should educate users about the risks of installing unverified apps or rooting devices, which could facilitate exploitation. Employ runtime protection and anomaly detection on mobile endpoints to identify suspicious memory corruption behaviors. Finally, maintain an incident response plan that includes mobile device compromise scenarios to quickly contain and remediate potential breaches.