The vulnerability is a CWE‑20 Improper Input Validation flaw located in the modem firmware of Unisoc (Shanghai) Technologies Co., Ltd. devices. A malformed packet or data stream can trigger an error path that leads to a device reset or other disruption, resulting in a denial‑of‑service condition. The attacker gains no execution privileges, and the impact fully compromises the availability of the modem function.

Affected systems are modem chipsets from Unisoc (Shanghai) Technologies Co., Ltd., specifically the T8100, T9100, T8200, and T8300 product families. No firmware version details are listed, so any build that incorporates the vulnerable modem logic may be susceptible.

The CVSS score of 7.5 indicates a high overall risk, and the EPSS score of less than 1% shows a very low but non‑zero likelihood of exploitation. The vulnerability is not cataloged in CISA KEV. Based on the description, it is inferred that the flaw can be triggered by remote network traffic directed at the modem’s control interfaces, and exposure depends on how those interfaces are exposed. An unauthenticated attacker may be able to cause repeated service interruptions without special privileges.