Cyber Resilience

CVE-2017-20224

CriticalPublic PoC

Published: 16 March 2026

Published
16 March 2026
Modified
14 April 2026
KEV Added
Patch
CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0104 59.5th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2017-20224 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Telesquare Sdt-Cs3B1 Firmware. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 40.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and CM-7 (Least Functionality).

Deeper analysis

CVE-2017-20224 affects the Telesquare SKT LTE Router SDT-CS3B1 version 1.2.0, manifesting as an arbitrary file upload vulnerability. The issue stems from enabled WebDAV HTTP methods, including PUT, DELETE, MKCOL, MOVE, COPY, and PROPPATCH, which permit attackers to upload malicious content without authentication.

Unauthenticated attackers can exploit this vulnerability remotely over the network with low attack complexity and no user interaction or privileges required, earning it a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). Exploitation allows uploading executable code for remote code execution, deleting files, or manipulating server content to cause denial of service, linked to CWE-434 (Unrestricted Upload of File with Dangerous Type).

Advisories documenting the vulnerability are available at https://cxsecurity.com/issue/WLB-2017120301, https://www.vulncheck.com/advisories/telesquare-skt-lte-router-sdt-cs3b1-webdav-arbitrary-file-upload, and https://www.zeroscience.mk/en/vulnerabilities/ZSL-2017-5446.php (ZSL-2017-5446).

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Telesquare SKT LTE Router SDT-CS3B1 version 1.2.0 contains an arbitrary file upload vulnerability that allows unauthenticated attackers to upload malicious content by exploiting enabled WebDAV HTTP methods. Attackers can use PUT, DELETE, MKCOL, MOVE, COPY, and PROPPATCH methods to upload…

more

executable code, delete files, or manipulate server content for remote code execution or denial of service.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

The vulnerability is an unauthenticated arbitrary file upload via exposed WebDAV on a public-facing router web interface, directly enabling exploitation of a public-facing application for RCE and full compromise.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2017-20223Same product: Telesquare Sdt-Cs3B1
CVE-2017-20222Same product: Telesquare Sdt-Cs3B1
CVE-2025-26005Same vendor: Telesquare
CVE-2025-26008Same vendor: Telesquare
CVE-2025-26007Same vendor: Telesquare
CVE-2025-26004Same vendor: Telesquare
CVE-2025-26010Same vendor: Telesquare
CVE-2025-26006Same vendor: Telesquare
CVE-2025-26011Same vendor: Telesquare
CVE-2025-26002Same vendor: Telesquare

Affected Assets

telesquare
sdt-cs3b1 firmware
1.2.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Enforces approved authorizations preventing unauthenticated access to WebDAV methods for arbitrary file uploads and manipulations.

prevent

Restricts system to least functionality by disabling unnecessary WebDAV HTTP methods, eliminating the exposure.

prevent

Monitors and controls communications at boundaries to block unauthorized WebDAV requests leading to file upload or RCE.

References