CVE-2025-20762 is a vulnerability classified under CWE-617 (Reachable Assertion) found in the modem firmware of various MediaTek chipsets, including models MT6835, MT6878, MT6897, MT6991, MT8676, MT8755, MT8792, MT8863, MT8873, and MT8883 among others. The flaw arises from improper error handling within the modem's software, which leads to a reachable assertion failure. When a user equipment (UE) device connects to a maliciously controlled rogue base station, the assertion triggers a system crash, resulting in a denial of service condition. Notably, exploitation does not require any privileges or user interaction, making it easier for attackers to cause disruption remotely. The vulnerability affects the availability of the device but does not compromise confidentiality or integrity. The CVSS v3.1 base score is 6.5, reflecting a medium severity due to the remote attack vector and lack of required privileges, balanced by the limited impact scope (availability only). MediaTek has assigned a patch ID (MOLY01685181) and issue ID (MSV-4760) for remediation, though no public patch link is currently available. No known exploits have been reported in the wild to date. This vulnerability primarily impacts devices using the affected MediaTek chipsets, which are widely deployed in smartphones and IoT devices globally.

The primary impact of CVE-2025-20762 is a remote denial of service condition on devices using affected MediaTek chipsets. This can cause devices to crash or become unresponsive when connecting to a rogue base station, potentially disrupting communications and device availability. For organizations, this could lead to service interruptions, especially in environments relying on cellular connectivity for critical operations or IoT deployments. The lack of required privileges or user interaction lowers the barrier for attackers to exploit this vulnerability, increasing the risk of widespread disruption in areas where rogue base stations can be deployed. However, the vulnerability does not allow data theft, modification, or privilege escalation, limiting its impact to availability. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once patches are widely deployed. The impact is more significant in regions with high usage of affected MediaTek chipsets and where adversaries have the capability to deploy rogue base stations.

1. Apply patches from MediaTek as soon as they become available to address the assertion failure in the modem firmware. 2. Network operators and organizations should deploy detection and mitigation systems to identify and block rogue base stations, such as using radio frequency monitoring tools and anomaly detection in cellular networks. 3. Device manufacturers should implement additional validation and error handling in modem firmware to prevent assertion failures. 4. Enterprises relying on cellular connectivity should consider multi-network redundancy or fallback mechanisms to maintain availability if one network is compromised. 5. Security teams should monitor threat intelligence feeds for any emerging exploits targeting this vulnerability. 6. End users should be advised to keep device firmware updated and avoid connecting to suspicious or unknown cellular networks. 7. Collaboration with mobile network operators to enhance base station authentication and integrity checks can reduce the risk of rogue base station attacks.