CVE-2021-47796 in SHC-150 Smart Wifi Camera
Summary
by MITRE • 01/16/2026
Denver SHC-150 Smart Wifi Camera contains a hardcoded telnet credential vulnerability that allows unauthenticated attackers to access a Linux shell. Attackers can connect to port 23 using the default credential to execute arbitrary commands on the camera's operating system.
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Analysis
by VulDB Data Team • 01/16/2026
The Denver SHC-150 Smart Wifi Camera presents a critical security vulnerability classified as CVE-2021-47796, which stems from a hardcoded telnet credential flaw that fundamentally compromises the device's security posture. This vulnerability resides within the camera's firmware implementation where default authentication credentials are embedded directly into the code rather than being dynamically generated or securely stored. The device listens on the standard telnet port 23 and accepts the hardcoded username and password combination, creating an unauthenticated access vector that bypasses all normal authentication mechanisms. This design flaw represents a fundamental failure in secure credential management practices and aligns with CWE-798, which specifically addresses the use of hardcoded credentials in software systems. The vulnerability exists across the entire product line and affects all devices shipped with the vulnerable firmware version, making it a widespread issue that impacts numerous installations in both residential and commercial environments.
The technical exploitation of this vulnerability enables attackers to establish a direct connection to the camera's Linux-based operating system through the telnet protocol, which operates without encryption and provides a command-line interface to the underlying system. Once connected, the attacker gains root-level access to the device's operating system, allowing them to execute arbitrary commands with full system privileges. This access level provides complete control over the camera's functionality, including the ability to capture and transmit video feeds, modify device configuration parameters, access stored media files, and potentially use the device as a pivot point for attacking other systems within the local network. The lack of encryption in the telnet protocol means that credentials and command inputs are transmitted in plaintext, creating additional exposure for attackers who may intercept these communications. The vulnerability represents a clear violation of the principle of least privilege and demonstrates a failure to implement proper network security controls as outlined in the NIST Cybersecurity Framework.
The operational impact of this vulnerability extends far beyond simple unauthorized access, creating significant risks for privacy, security, and network integrity. Attackers can leverage this access to monitor activities in the camera's coverage area, potentially capturing sensitive information or surveillance footage that may be used for malicious purposes. The compromised device can also serve as a launching point for broader network attacks, as it provides an entry point that bypasses traditional network security controls. This vulnerability directly impacts the confidentiality, integrity, and availability of the networked environment, as the attacker can modify device settings, delete stored data, or even create persistent backdoors for future access. The vulnerability's persistence across multiple devices indicates that organizations using these cameras face a systemic risk that cannot be addressed through simple configuration changes, requiring firmware updates or complete device replacement to remediate the issue effectively.
Mitigation strategies for CVE-2021-47796 must address both the immediate exploitation risk and the underlying design flaw that enabled the vulnerability. Organizations should immediately disable the telnet service on affected devices when possible, though this may not be feasible if the service is required for device management. The most effective long-term solution involves implementing firmware updates from the vendor that remove the hardcoded credentials and replace them with dynamically generated authentication mechanisms. Network segmentation should be implemented to isolate affected devices from critical network segments, and monitoring should be deployed to detect unauthorized telnet connections. Security controls should be implemented to detect and block telnet traffic at network boundaries, as this protocol is inherently insecure and should not be used in production environments. The vulnerability highlights the importance of secure development practices and proper credential management as outlined in the OWASP Secure Coding Practices, specifically addressing the need to avoid hardcoded credentials and implement proper authentication mechanisms that support secure password policies and account management. Additionally, organizations should consider implementing network access controls and regular security assessments to identify similar vulnerabilities in other networked devices that may be susceptible to the same class of attack.