CVE-2017-20223
Access Control in Telesquare Sdt-Cs3B1 Firmware 1.2.0
Raw vector
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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2017-20223 is a critical-severity Authorization Bypass Through User-Controlled Key (CWE-639) 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 at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2017-20223 is an insecure direct object reference vulnerability (CWE-639) affecting the Telesquare SKT LTE Router SDT-CS3B1 firmware version 1.2.0. This flaw allows attackers to bypass authorization controls by manipulating user-supplied input parameters, enabling direct referencing of system objects to retrieve sensitive information and access functionalities without proper access restrictions. The vulnerability carries 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), indicating critical severity due to its potential for high impacts on confidentiality, integrity, and availability.
Remote attackers require no privileges, low complexity, or user interaction to exploit this issue over the network. Successful exploitation grants unauthorized access to protected resources, allowing retrieval of sensitive data and execution of restricted operations, effectively undermining the device's access controls.
Advisories and related resources, including those from VulnCheck, CXSecurity, IBM X-Force, PacketStorm, and Exploit-DB, document the vulnerability and provide exploit details such as proof-of-concept code. Security practitioners should review these references for vendor-specific mitigation guidance or firmware updates.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2017-18939
Vulnerability Data
Telesquare SKT LTE Router SDT-CS3B1 firmware version 1.2.0 contains an insecure direct object reference vulnerability that allows attackers to bypass authorization and access resources by manipulating user-supplied input parameters. Attackers can directly reference objects in the system to retrieve sensitive…
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information and access functionalities without proper access controls.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Enforcing approved authorizations on every access request structurally stops a user-controlled key from reaching another user's data.
Requiring explicit access-control decisions on each request blocks unauthorized key-driven access.
Least-privilege restrictions limit the scope of data reachable even if a key check is bypassed.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.
Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing authorization checks but does not prevent the weakness in production.
Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.
Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.
Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.
Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.
Secure development lifecycle includes authorization design but does not itself implement runtime access checks.