CVE-2025-61619 is a vulnerability identified in the NR (New Radio) modem firmware of Unisoc (Shanghai) Technologies Co., Ltd. chipsets T8100, T9100, T8200, and T8300. These chipsets are integrated into mobile devices running Android versions 13 through 16. The root cause is improper input validation (classified under CWE-20), where the modem fails to correctly validate incoming data, leading to a potential system crash. This crash can be triggered remotely over the network without requiring any authentication or user interaction, making it a remote denial of service (DoS) vulnerability. The CVSS v3.1 score is 7.5, indicating high severity, with the attack vector being network-based (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). The impact is limited to availability (A:H), with no confidentiality or integrity compromise. The vulnerability affects a broad range of Android versions, increasing the scope of affected devices. No patches or exploits are currently publicly available, but the risk remains significant due to the ease of exploitation and potential disruption to mobile communications. The NR modem is critical for 5G connectivity, so exploitation could disrupt mobile network services on affected devices. This vulnerability highlights the importance of rigorous input validation in modem firmware to maintain system stability and availability.

For European organizations, the primary impact is the potential for remote denial of service attacks on mobile devices using Unisoc T8100/T9100/T8200/T8300 chipsets. This could disrupt mobile communications, affecting employees' ability to use smartphones for calls, messaging, and data services, which is critical for business operations and emergency communications. Telecommunications providers relying on devices with these chipsets may experience network instability or increased support costs due to device crashes. Critical sectors such as finance, healthcare, and government that depend on mobile connectivity for secure communications and operations could face operational disruptions. Additionally, IoT devices or embedded systems using these chipsets could be similarly affected, leading to broader availability issues. The lack of required authentication and user interaction increases the risk of widespread exploitation if attackers develop and deploy exploits. Although no known exploits exist yet, the vulnerability's characteristics make it a plausible target for attackers aiming to cause service outages or disrupt mobile infrastructure.

1. Device manufacturers and vendors should prioritize developing and distributing firmware or software updates that address the input validation flaw in the NR modem firmware. 2. Mobile device users and organizations should apply these updates promptly once available to mitigate the risk of exploitation. 3. Network operators and enterprises should implement network-level filtering and anomaly detection to identify and block malformed or suspicious NR modem traffic that could trigger the crash. 4. Employ mobile device management (MDM) solutions to monitor device health and remotely enforce updates or isolate affected devices if instability is detected. 5. For critical infrastructure, consider deploying redundant communication channels or failover mechanisms to maintain connectivity if mobile devices become unavailable. 6. Collaborate with Unisoc and device OEMs to receive timely vulnerability disclosures and patches. 7. Conduct penetration testing and security assessments focusing on NR modem components to identify any residual or related vulnerabilities. 8. Educate security teams about this vulnerability to ensure rapid incident response if exploitation attempts are detected.