CVE-2025-20792 is a vulnerability classified under CWE-617 (Reachable Assertion) affecting a broad range of MediaTek modem chipsets, including MT2735, MT6833 series, MT6853 series, MT6873 series, MT6880 series, MT6890 series, and MT8791T. The flaw resides in the modem firmware's input validation logic, where improper handling of certain inputs can trigger an assertion failure, causing the modem subsystem to crash. This results in a denial of service condition on the device. The vulnerability can be exploited remotely by an attacker who sets up a rogue base station that a user equipment (UE) connects to, requiring no user interaction and minimal privileges. The attack complexity is high, meaning the attacker must have precise control over the rogue base station environment. The impact is limited to availability, with no confidentiality or integrity compromise reported. The vulnerability affects devices running Modem NR15 firmware versions prior to the patch MOLY01717526. While no public exploits are known, the broad chipset coverage and potential for remote DoS make this a significant concern for mobile device users and network operators. The vulnerability was published on December 2, 2025, with a CVSS v3.1 score of 5.3, indicating a medium severity level.

For European organizations, the primary impact of CVE-2025-20792 is the potential for remote denial of service on mobile devices using affected MediaTek chipsets. This can disrupt critical communications, especially for sectors relying heavily on mobile connectivity such as emergency services, transportation, finance, and remote workforces. Telecom operators may face increased support costs and customer dissatisfaction if rogue base stations are used to exploit this vulnerability. Industrial IoT devices and embedded systems using these chipsets could also experience outages, affecting operational continuity. Although the vulnerability does not compromise data confidentiality or integrity, the loss of availability can have cascading effects on business operations and service delivery. The requirement for connection to a rogue base station limits the attack surface but does not eliminate risk, particularly in urban or high-density areas where attackers might deploy such infrastructure covertly.

1. Apply the official MediaTek patch MOLY01717526 as soon as it becomes available for all affected devices to remediate the vulnerability at the firmware level. 2. Network operators and enterprises should implement detection and mitigation mechanisms for rogue base stations, including radio frequency monitoring and anomaly detection systems. 3. Encourage users to update their device firmware regularly and avoid connecting to untrusted or unknown cellular networks. 4. Deploy mobile device management (MDM) solutions that can enforce firmware updates and monitor device connectivity patterns. 5. Collaborate with telecom providers to enhance base station authentication and integrity checks to prevent rogue base station attacks. 6. For critical infrastructure relying on affected chipsets, consider network segmentation and fallback communication methods to maintain availability during potential DoS events. 7. Conduct regular security assessments and penetration testing focused on cellular network vulnerabilities within organizational environments.