Telesquare SKT LTE Router SDT-CS3B1 CSRFによるシステムコマンド実行

An attacker exploiting this CSRF vulnerability can gain unauthorized access to the Telesquare SDT-CS3B1 LTE Router and execute arbitrary system commands with router privileges. This could lead to complete compromise of the device, including data exfiltration, configuration modification, and potentially, lateral movement within the network. The impact is particularly severe in environments where the router handles sensitive data or acts as a gateway to internal resources. Successful exploitation could allow an attacker to disrupt network services, intercept traffic, or even use the router as a launchpad for further attacks.

Organizations utilizing the Telesquare SDT-CS3B1 LTE Router in industrial control systems, remote site connectivity, or any environment where the router handles sensitive data are at risk. Specifically, deployments relying on default configurations or lacking robust access controls are particularly vulnerable.

• linux / server:

journalctl -u telesquare_router | grep -i "csrf"

• generic web:

curl -I <router_ip>/admin | grep -i "referer"

1. 2026-03-16Disclosure

   disclosure

1. 予約済み2026-03-15
2. 公開日2026-03-16
3. 更新日2026-04-07
4. EPSS 更新日2026-04-12

The primary mitigation for CVE-2017-20221 is to upgrade the Telesquare SDT-CS3B1 LTE Router to a patched firmware version (unavailable at the time of writing). As an interim measure, implement a Web Application Firewall (WAF) with CSRF protection rules to filter out malicious requests. Additionally, enforce strong password policies and multi-factor authentication for router administrative accounts. Regularly review router logs for suspicious activity. Consider implementing network segmentation to limit the router's access to sensitive resources.