CVE-2025-20936 is an improper authorization vulnerability classified under CWE-285 found in the HDCP (High-bandwidth Digital Content Protection) trustlet on Samsung Mobile devices. This vulnerability exists in versions prior to the Samsung Mobile Security Release (SMR) April 2025 Release 1. The flaw allows a local attacker who already has shell-level privileges on the device to escalate their privileges to root. The HDCP trustlet is a trusted execution environment component responsible for managing protected content streams, and improper access control here means that certain privileged operations can be accessed without proper authorization checks. The vulnerability has a CVSS v3.1 base score of 8.8, indicating high severity, with attack vector Local (AV:L), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), and scope changed (S:C). The impact on confidentiality, integrity, and availability is high, as root access grants full control over the device. No public exploits have been reported yet, but the vulnerability poses a significant risk if local shell access is obtained. The vulnerability was reserved in November 2024 and published in April 2025. Samsung Mobile devices worldwide running affected firmware versions are vulnerable until patched.

This vulnerability allows attackers with limited local access to escalate privileges to root, effectively gaining full control over the affected Samsung Mobile device. With root privileges, attackers can bypass security controls, access sensitive data, install persistent malware, and disrupt device operations. This compromises user confidentiality, device integrity, and availability. Organizations relying on Samsung Mobile devices for sensitive communications or operations face risks of data breaches, espionage, and operational disruption. The requirement for local shell access limits remote exploitation but does not eliminate risk, especially in environments where devices may be physically accessible or compromised through other means. The scope of affected devices is broad given Samsung's global market share, potentially impacting millions of users and enterprise deployments. The vulnerability could also be leveraged as a stepping stone for further attacks within enterprise networks if compromised devices are connected to corporate resources.

1. Apply the Samsung Mobile Security Release (SMR) April 2025 Release 1 update as soon as it becomes available to patch the vulnerability. 2. Restrict local shell access on Samsung Mobile devices by enforcing strong authentication, disabling unnecessary debugging interfaces, and limiting physical access. 3. Implement mobile device management (MDM) solutions to monitor and control device configurations and access permissions. 4. Conduct regular audits of device privilege levels and installed applications to detect unauthorized access or privilege escalations. 5. Educate users about the risks of granting shell or developer access and discourage rooting or jailbreaking devices. 6. Employ endpoint detection and response (EDR) tools capable of detecting suspicious privilege escalation activities on mobile devices. 7. For enterprise environments, isolate mobile devices from critical network segments to reduce lateral movement risk if compromised. 8. Monitor threat intelligence sources for any emerging exploit code or attack campaigns targeting this vulnerability.