The vulnerability arises from improper input validation within the modem firmware. The flaw allows an attacker to craft malformed data that, when processed, causes the modem to become unresponsive. This results in a loss of service availability without requiring any privileged access. The impact is limited to the affected device’s availability rather than confidentiality or integrity.

Unisoc (Shanghai) Technologies Co., Ltd. exposes the issue in its T8100, T9100, T8200, and T8300 modem families. No specific firmware version data are listed, so any device using these chipsets is potentially affected until a patch is applied.

The CVSS score of 7.5 indicates a high risk of disruption. The EPSS score of < 1% indicates that the probability of exploitation is low, but the lack of privilege escalation and the potential for remote exploitation suggest that an attacker with network access can trigger the denial of service by sending carefully crafted packets. The vulnerability is not yet listed in the CISA KEV catalog, but its availability impact warrants prompt mitigation.