CVE-2017-20223 in SDT-CS3B1
Summary
by MITRE • 03/16/2026
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 information and access functionalities without proper access controls.
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Analysis
by VulDB Data Team • 03/16/2026
The insecure direct object reference vulnerability present in Telesquare SKT LTE Router SDT-CS3B1 firmware version 1.2.0 represents a critical authorization bypass flaw that fundamentally undermines the router's security architecture. This vulnerability classifies under CWE-284 Access Control Issues, specifically manifesting as an improper access control condition that allows unauthorized users to directly manipulate object references within the system. The flaw exists in the router's web-based administration interface where user-supplied parameters are not properly validated or sanitized before being used to access internal system resources. Attackers can exploit this weakness by directly manipulating URL parameters, form fields, or API calls to access restricted functionalities and sensitive data that should only be available to authenticated administrators.
The technical implementation of this vulnerability stems from the router's failure to enforce proper access control checks when processing user input. When legitimate administrative functions are accessed through the web interface, the system relies on predictable object references that can be easily manipulated by attackers. The firmware version 1.2.0 lacks proper session management and object validation mechanisms, allowing malicious actors to traverse the application's object hierarchy without proper authentication. This weakness enables attackers to access sensitive information such as system configuration files, user credentials, network settings, and administrative interfaces that should remain protected from unauthorized access. The vulnerability operates at the application layer and can be exploited through simple parameter manipulation techniques that do not require advanced exploitation skills or specialized tools.
The operational impact of this vulnerability is severe and multifaceted, creating significant risks for network security and data integrity. An attacker who successfully exploits this vulnerability can gain complete administrative control over the router, enabling them to modify network configurations, redirect traffic, implement man-in-the-middle attacks, and potentially establish persistent backdoors within the network infrastructure. The compromised device can serve as a pivot point for lateral movement within the local network, allowing attackers to access connected devices and systems that may not be directly exposed to the internet. This vulnerability also poses risks to data confidentiality and integrity, as attackers can extract sensitive configuration information that may reveal network topology, security settings, and other proprietary information. The impact extends beyond the immediate device to potentially affect the broader network security posture of organizations relying on the router for connectivity.
Mitigation strategies for this vulnerability should include immediate firmware updates from the vendor to address the insecure direct object reference implementation. Organizations should implement network segmentation and access controls to limit the potential impact of a compromised device, while also deploying network monitoring solutions to detect suspicious traffic patterns that may indicate exploitation attempts. The implementation of proper input validation, parameter sanitization, and access control mechanisms should be enforced at the application level to prevent similar vulnerabilities from occurring in future deployments. Network administrators should also conduct regular security assessments of network infrastructure devices to identify and remediate similar authorization bypass vulnerabilities. This vulnerability aligns with ATT&CK technique T1078 Valid Accounts, as it allows attackers to bypass authentication mechanisms and gain administrative privileges through manipulated object references rather than traditional credential theft methods. Regular security audits and vulnerability assessments should be performed to ensure that all network devices maintain proper access controls and that firmware updates are applied promptly to address known security issues.