CVE-2025-20725 is an out-of-bounds write vulnerability classified under CWE-787, discovered in the IMS (IP Multimedia Subsystem) service of MediaTek chipsets. The vulnerability arises due to a missing bounds check in the IMS service code, which can lead to memory corruption through an out-of-bounds write operation. This flaw affects a wide range of MediaTek chipsets, including MT2735, MT2737, MT6739, MT6761, MT6762 series, MT6763, MT6765 series, MT6767, MT6768, MT6769 series, MT6771, MT6833 series, MT6853 series, MT6855 series, MT6873 series, MT6875 series, MT6877 series, MT6879, MT6880 series, MT6883, MT6885, MT6886, MT6889, MT6890 series, MT6980 series, MT6983 series, MT6985 series, MT6989 series, MT6990, MT8666, MT8667, MT8673, MT8675, MT8765 series, MT8766 series, MT8768, MT8771, MT8786, MT8788 series, MT8791 series, MT8795T, MT8797, MT8798, and MT8893. The affected modem firmware versions are LR12A, NR15, and NR16. Exploitation occurs remotely when a user equipment (UE) connects to a malicious rogue base station controlled by an attacker, requiring no user interaction or additional execution privileges. Successful exploitation can lead to remote escalation of privilege, enabling the attacker to compromise device confidentiality, integrity, and availability. The vulnerability has a CVSS v3.1 base score of 7.5, indicating high severity, with attack vector network (AV:N), attack complexity high (AC:H), privileges required low (PR:L), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild. The vendor has assigned patch ID MOLY01671924 and issue ID MSV-4620 for remediation. This vulnerability poses a significant risk to mobile devices using affected MediaTek chipsets, especially in environments where devices may connect to untrusted or rogue cellular base stations.

For European organizations, the impact of CVE-2025-20725 is substantial due to the widespread use of MediaTek chipsets in consumer and enterprise mobile devices, including smartphones, IoT devices, and embedded systems. The vulnerability enables remote attackers to escalate privileges without user interaction, potentially allowing unauthorized access to sensitive data, disruption of communications, or installation of persistent malware. Critical sectors such as telecommunications, finance, healthcare, and government could face data breaches, service outages, or espionage risks. The ability to exploit this vulnerability via rogue base stations is particularly concerning in urban and industrial environments where attackers could deploy such infrastructure covertly. Additionally, the vulnerability could undermine trust in mobile network security and complicate compliance with European data protection regulations like GDPR if personal data is compromised. The absence of known exploits currently provides a window for proactive defense, but the high severity and ease of remote exploitation necessitate urgent mitigation to prevent potential large-scale attacks.

1. Immediate application of vendor-supplied patches (MOLY01671924) to all affected devices and modems running LR12A, NR15, or NR16 firmware versions is critical. 2. Network operators and enterprises should implement detection mechanisms for rogue base stations, including anomaly-based monitoring and radio frequency scanning, to identify and block unauthorized cellular infrastructure. 3. Employ mobile device management (MDM) solutions to enforce firmware updates and restrict device connectivity to trusted networks only. 4. Encourage users to avoid connecting to unknown or suspicious cellular networks, especially in sensitive environments. 5. Collaborate with telecom providers to enhance base station authentication protocols and strengthen IMS security configurations. 6. Conduct regular security audits and penetration testing focusing on mobile network interfaces and IMS components. 7. For IoT deployments using affected chipsets, isolate devices on segmented networks and monitor for unusual behavior indicative of exploitation attempts. 8. Maintain up-to-date threat intelligence feeds to stay informed about emerging exploits targeting this vulnerability. 9. Educate security teams and end-users about the risks of rogue base stations and the importance of timely updates. 10. Consider deploying endpoint detection and response (EDR) tools capable of identifying memory corruption or privilege escalation attempts on mobile devices.