An unauthenticated remote reboot flaw in the Telesquare SDT‑CS3B1 LTE router allows an attacker to trigger a device restart without credential validation. Rebooting the router causes a loss of connectivity for any networks that rely on the device, resulting in a denial‑of‑service condition. The underlying weakness is a missing authentication check for a critical operation, a type of flaw classified as CWE‑306.

The vulnerability affects the Telesquare SDT‑CS3B1 router running firmware versions 1.1.0 and 1.2.0. Attackers target the administrative web interface exposed on the router’s network interfaces.

The CVSS score of 8.7 indicates a high severity, and the EPSS score of less than 1% suggests a low probability of exploitation in the wild. Because the flaw can be triggered with an unauthenticated HTTP POST request to the lte.cgi endpoint, the attack is likely to be carried out from any host that can reach the device’s web interface, whether locally or from a remote network. The flaw is classified as a remote denial‑of‑service and is not listed in CISA’s KEV catalog.