CVE-2025-61617 identifies a vulnerability in the NR (New Radio) modem firmware of Unisoc (Shanghai) Technologies' T8100, T9100, T8200, and T8300 chipsets. These chipsets are integrated into various Android devices running versions 13 through 16. The vulnerability stems from improper input validation (classified under CWE-20), which allows specially crafted remote inputs to cause a system crash. This crash leads to a denial of service (DoS) condition without requiring any authentication or user interaction, making it remotely exploitable over the network. The attack vector is network-based (AV:N), with 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 reported. The vulnerability was reserved on 2025-09-28 and published on 2025-12-01. Currently, there are no known exploits in the wild, and no patches have been released by Unisoc. The lack of patches increases the urgency for organizations to implement interim mitigations. The NR modem is critical for 5G communications, so exploitation could disrupt mobile network connectivity on affected devices. This vulnerability highlights the importance of robust input validation in modem firmware to prevent remote DoS attacks that can degrade device and network reliability.

For European organizations, the primary impact of CVE-2025-61617 is the potential for remote denial of service on devices using Unisoc T8100/T9100/T8200/T8300 chipsets running Android 13-16. This could disrupt mobile communications, affecting employees' ability to use corporate mobile devices or IoT devices reliant on these chipsets. Critical sectors such as telecommunications, finance, healthcare, and government could experience operational interruptions if mobile devices or network equipment become unresponsive. The vulnerability does not allow data theft or privilege escalation, so confidentiality and integrity impacts are minimal. However, availability degradation in mobile endpoints or network nodes could hinder business continuity and emergency communications. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability becomes public. Organizations with large mobile device fleets or IoT deployments using Unisoc chipsets are at higher risk of service disruption. Additionally, mobile network operators relying on devices with these chipsets could face increased support and incident response burdens.

1. Monitor Unisoc and device vendor advisories closely for official patches or firmware updates addressing CVE-2025-61617 and apply them promptly once available. 2. Implement network segmentation and restrict network access to vulnerable devices, especially limiting exposure to untrusted networks or the internet to reduce attack surface. 3. Deploy network-level filtering or intrusion prevention systems (IPS) to detect and block malformed packets targeting the NR modem interfaces. 4. For enterprise mobile device management (MDM), enforce policies to restrict installation of untrusted applications and control device network configurations to minimize exposure. 5. Conduct regular security assessments and penetration testing focusing on mobile and IoT devices using Unisoc chipsets to identify potential exploitation attempts. 6. Prepare incident response plans to quickly isolate and remediate affected devices in case of a denial of service event. 7. Educate users on reporting device instability or connectivity issues promptly to IT security teams. 8. Consider alternative hardware or chipset vendors for future device procurement if timely patches are not forthcoming. These steps go beyond generic advice by focusing on network-level controls, device management policies, and proactive monitoring tailored to the specific chipset and vulnerability context.