What is the CVSS score of CVE-2017-20222?

CVE-2017-20222 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N. EPSS exploitation probability: 0.2%.

Is there a public PoC exploit available for CVE-2017-20222?

Yes, a public proof-of-concept exploit is available for CVE-2017-20222. Prioritise patching immediately. EPSS: 0.2%.

How to fix or mitigate CVE-2017-20222?

Within 24 hours: Inventory all Telesquare SKT LTE Router SDT-CS3B1 devices in production and document their network location and criticality. Within 7 days: Implement network segmentation to restrict access to the lte.cgi endpoint (block POST requests to management interfaces), deploy WAF rules to filter malicious payloads targeting this endpoint, and disable remote management if not operationally required. Within 30 days: Evaluate replacement with alternative router hardware from vendors with active security patching, or contact Telesquare directly for firmware updates or extended support; establish monitoring for exploitation attempts and configure router restarts logs for incident detection.

Sdt Cs3b1 CVE-2017-20222

EUVD-2017-18938 HIGH

Missing Authentication for Critical Function (CWE-306)

2026-03-16 VulnCheck

Authentication Bypass Denial Of Service Sdt Cs3b1 Telesquare

8.7

CVSS 4.0 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-306 OWASP Top 10:2025 A07:2025 - Authentication Failures ASVS 5.0 V6 - Authentication Authentication required for critical functions MITRE ATT&CK 1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	While the CVSS 7.5 score indicates high severity (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), the real-world risk requires nuanced assessment. The attack is network-accessible with low complexity and requires no privileges or user interaction, making it easily exploitable. Multiple public exploits exist (Exploit-DB, PacketStorm Security), significantly increasing risk. However, the impact is limited to availability only - no data breach or system compromise occurs. The vulnerability is not in CISA KEV, suggesting no known active exploitation in the wild. For organizations using these routers, this represents a moderate-to-high priority issue primarily due to the ease of exploitation and potential for automated attacks causing service disruption.
Exploit ScenarioDerived	An attacker identifies a Telesquare SDT-CS3B1 router through network scanning or Shodan searches. Using readily available exploit code from Exploit-DB (43401) or PacketStorm (145555), they send a simple HTTP POST request to http://[router-ip]/lte.cgi with the parameter 'Command=Reboot'. The router immediately restarts without any authentication check, disrupting all connected services. This attack can be automated to repeatedly reboot the device every few minutes, creating persistent denial of service. In a targeted scenario, attackers could time the reboots to coincide with critical business operations or combine with other attacks during the reboot window.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 16, 2026

An unauthenticated remote reboot vulnerability exists in the Telesquare SKT LTE Router SDT-CS3B1 firmware version 1.2.0, allowing attackers to trigger device restarts without any authentication by sending specially crafted POST requests to the lte.cgi endpoint. This vulnerability has a publicly available proof-of-concept exploit and enables denial of service attacks against affected routers. The vulnerability has been assigned a high CVSS score of 7.5 due to the complete availability impact and lack of authentication requirements.

RemediationAI

No patch information or updated firmware version is mentioned in any of the provided references. Primary mitigation involves restricting network access to the router's management interface through firewall rules or access control lists. Organizations should: 1) Limit access to the lte.cgi endpoint to trusted IP addresses only, 2) Place the router management interface on a separate management VLAN, 3) Contact Telesquare for firmware updates addressing this vulnerability, 4) Monitor for unusual reboot patterns that could indicate exploitation attempts. The VulnCheck advisory (https://www.vulncheck.com/advisories/telesquare-skt-lte-router-sdt-cs3b1-unauthenticated-remote-reboot) may contain additional vendor-specific guidance.

Affected VersionsENISA

SDT-CS3B1 1.2.0

Affected Packages

euvd sdt_cs3b1 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The vulnerability affects the Telesquare SKT LTE Router model SDT-CS3B1 running firmware version 1.2.0, as identified by CPE string cpe:2.3:a:telesquare:sdt-cs3b1:*:*:*:*:*:*:*:*. The root cause is CWE-306 (Missing Authentication for Critical Function), where the lte.cgi endpoint accepts POST requests with the 'Command=Reboot' parameter without verifying the sender's identity. This CGI script appears to be a management interface that should require authentication but fails to implement any access controls, allowing anyone who can reach the router's web interface to trigger administrative actions.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.7 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

None

Vulnerable system: Integrity

None

Vulnerable system: Availability

High

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

CVSS changed

Apr 14, 2026 - 17:07 NVD

7.5 (HIGH) 8.7 (HIGH)

PoC Detected

Mar 16, 2026 - 14:53 vuln.today

Public exploit code

CVE Published

Mar 16, 2026 - 01:28 nvd

HIGH 7.5

DescriptionCVE.org

Telesquare SKT LTE Router SDT-CS3B1 software version 1.2.0 contains an unauthenticated remote reboot vulnerability that allows attackers to trigger device reboot without authentication. Attackers can send POST requests to the lte.cgi endpoint with the Command=Reboot parameter to cause denial of service by forcing the router to restart.

Executive ViewAI

Why It Matters

An unauthenticated remote reboot vulnerability in Telesquare SKT LTE Router SDT-CS3B1 (firmware 1.2.0) allows attackers to remotely disable affected devices without credentials, creating a denial of service risk for any organization relying on these routers for network connectivity. With public exploits available and no vendor patch forthcoming, immediate action is required to identify affected devices and implement protective measures to prevent service disruption.

Business Impact: High

Compensating Controls

Network segmentation: isolate management interfaces behind firewall rules restricting POST access to lte.cgi. WAF/IDS rules: block POST requests containing exploit payloads to vulnerable endpoint. Disable remote management: if not required operationally, disable HTTP/HTTPS management access externally. SNMP/SSH-only management: restrict administrative access to secure protocols only. Monitor: enable device restart logging and configure alerts for unexpected reboot events. Consider replacement: evaluate upgrading to alternative routers with active vendor security support.

Threat Intelligence Overview

EPSS Score

0.2%

Top 60% exploitable

Exploit

POC

Public exploit code exists

Data Quality

5 sources

Confidence: Medium

EUVD

NVD

CVE.org

EPSS

Exploit-DB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.2%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.