CVE-2025-20743 is a use-after-free vulnerability classified under CWE-416, affecting the clkdbg component in a wide range of MediaTek System on Chips (SoCs) including MT2718, MT6761, MT6765, MT6768, MT6781, MT6853, MT6877, MT6886, MT6893, MT6897, MT6899, MT6983, MT6989, MT6991, MT8113, MT8163, MT8168, MT8169, MT8183, MT8186, MT8188, MT8195, MT8196, MT8321, MT8365, MT8385, MT8390, MT8391, MT8512, MT8516, MT8519, MT8676, MT8678, MT8695, MT8696, MT8698, MT8755, MT8766, MT8768, MT8771, MT8775, MT8781, MT8786, MT8788E, MT8791T, MT8792, MT8793, MT8796, MT8797, MT8798, MT8873, MT8883, and MT8893. These SoCs are embedded in Android devices running versions 14.0 through 16.0. The vulnerability occurs due to improper handling of memory in the clkdbg module, leading to use-after-free conditions that can be exploited to escalate privileges locally. Exploitation requires the attacker to have already obtained System-level privileges, meaning the attacker must have significant access beforehand. However, no user interaction is required, which simplifies exploitation once System access is gained. The vulnerability could allow an attacker to execute arbitrary code or gain higher privileges, potentially compromising device integrity and confidentiality. While no public exploits are known, the vulnerability is significant due to the broad range of affected chipsets and the critical nature of privilege escalation. MediaTek has identified the issue (Patch ID: ALPS10136671; Issue ID: MSV-4651), but no patch links are currently provided. This vulnerability is particularly relevant for mobile devices used in enterprise and government sectors where secure privilege boundaries are essential.

For European organizations, the impact of CVE-2025-20743 is primarily on mobile devices using MediaTek chipsets running Android 14 to 16. The vulnerability enables local privilege escalation from System-level access to potentially higher privileges, which could lead to unauthorized access to sensitive data, installation of persistent malware, or disruption of device operations. This is especially critical for sectors such as finance, healthcare, government, and critical infrastructure where mobile devices are used for sensitive communications and operations. The lack of user interaction requirement means that once an attacker has System access, they can exploit this vulnerability without alerting the user, increasing stealth and risk. The broad range of affected chipsets means many devices in use across Europe could be vulnerable, potentially impacting large user bases. This could undermine trust in mobile device security and complicate compliance with data protection regulations like GDPR if personal data is compromised. Additionally, the vulnerability could be leveraged as part of multi-stage attacks targeting enterprise networks via compromised mobile endpoints.

1. Apply patches promptly once MediaTek or device manufacturers release updates addressing CVE-2025-20743. 2. Restrict System-level access on devices to trusted applications and users only, minimizing the risk of initial System privilege compromise. 3. Employ mobile device management (MDM) solutions to enforce security policies, monitor for privilege escalations, and control application permissions. 4. Conduct regular security audits and endpoint detection on mobile devices to identify unusual behaviors indicative of exploitation attempts. 5. Educate users and administrators about the risks of privilege escalation vulnerabilities and the importance of applying updates. 6. For organizations deploying custom Android builds or firmware, review clkdbg and related components for secure memory management practices. 7. Implement network segmentation and zero-trust principles to limit the impact of compromised mobile devices on broader enterprise networks. 8. Monitor threat intelligence feeds for emerging exploits or indicators of compromise related to this vulnerability to enable rapid response.