CVE-2025-20793 is a vulnerability classified under CWE-476 (NULL Pointer Dereference) affecting numerous MediaTek modem chipsets including MT2735, MT2737, MT6813, MT6815, and many others spanning multiple modem versions (NR15 through NR17R). The vulnerability stems from incorrect error handling in the modem firmware, which can cause the system to dereference a NULL pointer, resulting in a system crash. This crash leads to a denial of service condition on the affected device. The attack vector involves a user equipment (UE) connecting to a rogue base station controlled by an attacker. No additional execution privileges or user interaction are required, making the attack remotely executable and stealthy. The flaw impacts the modem’s ability to maintain stable network connectivity, potentially disrupting mobile communications. The vulnerability was reserved in November 2024 and published in January 2026. Although no public exploits are known, the broad range of affected chipsets and the critical role of modems in mobile devices make this a significant threat. The patch identified as MOLY01430930 addresses the issue but requires deployment by device manufacturers and carriers. The vulnerability primarily impacts device availability, with indirect effects on confidentiality and integrity being minimal. The lack of a CVSS score necessitates a severity assessment based on technical factors.

For European organizations, the primary impact of CVE-2025-20793 is the potential for remote denial of service on mobile devices using affected MediaTek modems. This can disrupt critical communications, especially for enterprises relying on mobile networks for operational continuity, emergency services, or IoT deployments. Telecom providers may experience increased network instability or customer complaints due to devices crashing when connecting to rogue or misconfigured base stations. The vulnerability could be exploited by attackers setting up rogue base stations in public or sensitive areas to cause widespread service outages. This risk extends to sectors such as finance, healthcare, transportation, and government, where mobile connectivity is essential. Additionally, the disruption could affect supply chains and remote work capabilities. The lack of user interaction and privilege requirements lowers the barrier for exploitation, increasing the threat surface. While confidentiality and data integrity are less impacted, availability degradation can have cascading effects on business operations and public safety.

1. Deploy the official patch (MOLY01430930) as soon as it becomes available from device manufacturers or carriers to remediate the NULL pointer dereference flaw. 2. Implement network monitoring solutions to detect and alert on the presence of rogue base stations or suspicious network behavior indicative of an attack. 3. Encourage users and organizations to update device firmware regularly and verify that modems are running secure, updated versions. 4. Telecom operators should strengthen base station authentication and validation mechanisms to prevent unauthorized rogue stations from attracting UE connections. 5. Employ anomaly detection on mobile network traffic to identify unusual disconnections or crashes that may signal exploitation attempts. 6. For critical infrastructure, consider multi-factor communication channels or fallback mechanisms to maintain connectivity during outages. 7. Collaborate with device vendors to ensure timely security updates and transparency regarding vulnerability status. 8. Educate end-users and IT staff about the risks of connecting to unknown or untrusted networks, even though user interaction is not required for this exploit, awareness can help in broader threat mitigation.