CVE-2025-21044 is a security vulnerability classified as an out-of-bounds write (CWE-787) affecting the fingerprint trustlet component in Samsung Mobile devices released before the SMR Oct-2025 Release 1 update. The fingerprint trustlet is a trusted execution environment (TEE) component responsible for securely handling fingerprint data and authentication processes. The vulnerability allows a local attacker with elevated privileges to write data beyond the allocated memory boundaries, which can corrupt memory, potentially leading to unauthorized code execution or data manipulation within the trustlet environment. This can compromise the confidentiality and integrity of biometric data and possibly allow privilege escalation or bypass of security controls. The CVSS v3.1 score is 5.7, reflecting medium severity, with the vector indicating local attack vector (AV:L), high attack complexity (AC:H), requiring privileged access (PR:H), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality and integrity (C:H/I:H) but no impact on availability (A:N). No public exploits are known, and Samsung has reserved the CVE since November 2024, publishing details in October 2025. The vulnerability affects all Samsung Mobile devices using the vulnerable fingerprint trustlet prior to the specified patch, but exact affected versions are not listed. The primary risk is local attackers who already have privileged access, such as through other vulnerabilities or insider threats, leveraging this flaw to further compromise device security.

For European organizations, the impact centers on the potential compromise of biometric authentication security on Samsung Mobile devices, which are widely used across Europe. Successful exploitation could lead to unauthorized access to sensitive corporate or personal data protected by fingerprint authentication, undermining device integrity and user trust. This could facilitate lateral movement within corporate networks if devices are used as authentication tokens or for accessing enterprise resources. The confidentiality and integrity of biometric data are at risk, which may have regulatory implications under GDPR regarding biometric data protection. Although the vulnerability requires local privileged access, it could be exploited by malware or malicious insiders. The lack of availability impact reduces the risk of denial-of-service but does not diminish the threat to data security. Organizations relying heavily on Samsung Mobile devices for secure authentication should consider this vulnerability a moderate risk until patched.

1. Apply the SMR Oct-2025 Release 1 update from Samsung as soon as it becomes available to remediate the vulnerability. 2. Restrict local privileged access on Samsung Mobile devices by enforcing strict device management policies, including limiting installation of untrusted applications and disabling unnecessary services. 3. Employ mobile threat defense solutions that can detect suspicious local privilege escalation attempts or abnormal behavior on devices. 4. Monitor device logs and security alerts for signs of exploitation attempts or anomalous activity related to fingerprint authentication components. 5. Educate users and administrators about the risks of granting elevated privileges to applications or users on mobile devices. 6. Consider multi-factor authentication methods that do not solely rely on fingerprint biometrics to reduce reliance on potentially compromised authentication factors. 7. For high-security environments, implement device attestation and integrity verification to detect tampering with trusted components.