CVE-2019-14920 in Smart Energy Router SG600R2
Summary
by MITRE
Billion Smart Energy Router SG600R2 Firmware v3.02.rc6 allows an authenticated attacker to gain root execution privileges over the device via a hidden etc_ro/web/adm/system_command.asp shell feature.
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Analysis
by VulDB Data Team • 03/20/2024
The vulnerability CVE-2019-14920 represents a critical security flaw in the Billion Smart Energy Router SG600R2 firmware version 3.02.rc6 which exposes a hidden administrative interface component. This issue falls under the category of privilege escalation vulnerabilities and is classified as CWE-269 Improper Privilege Management. The vulnerability stems from the presence of a hidden shell feature within the web administration interface that is not properly secured or documented, allowing authenticated users to execute arbitrary commands with root privileges. The affected file system path system_command.asp within the etc_ro/web/adm directory structure demonstrates poor security design where administrative functionality is exposed without adequate access controls. This vulnerability directly impacts the router's security posture by creating an unauthorized code execution vector that bypasses normal authentication mechanisms and privilege levels.
The technical implementation of this flaw involves a hidden administrative web page that remains accessible to authenticated users who should not have root-level access to the device. The system_command.asp component serves as a backdoor interface that allows command execution, effectively providing attackers with complete control over the router's operating system. This represents a serious violation of the principle of least privilege, as legitimate administrative functions should not be accessible to users who do not have proper authorization. The vulnerability is particularly concerning because it operates silently within the firmware without normal user interface indicators, making detection extremely difficult for network administrators who may not be aware of the hidden interface's existence. The attack surface is further expanded by the fact that this functionality is not properly secured through access control lists or authentication checks that would normally prevent unauthorized privilege escalation.
From an operational perspective, this vulnerability creates significant risks for network security and device integrity. An authenticated attacker who gains access to the router through legitimate means can escalate their privileges to root level, enabling them to modify system configurations, install malicious software, or extract sensitive data from the device. The impact extends beyond individual device compromise as compromised routers can serve as entry points for broader network attacks, potentially allowing lateral movement within corporate networks or enabling man-in-the-middle attacks on network traffic. This vulnerability also impacts compliance with security standards such as NIST SP 800-53 and ISO 27001, as it represents a failure to maintain proper access controls and privilege management. The presence of such a backdoor interface violates fundamental security principles and can lead to substantial financial losses through data breaches, service disruption, or regulatory penalties.
The mitigation strategy for CVE-2019-14920 requires immediate firmware updates from the vendor to address the hidden administrative interface and remove the unauthorized privilege escalation capability. Network administrators should also implement network segmentation and monitoring to detect unusual command execution patterns that might indicate exploitation attempts. Additional protective measures include disabling unnecessary web interfaces, implementing strict access controls for administrative functions, and conducting regular security audits to identify similar hidden components within network infrastructure. The vulnerability demonstrates the importance of security-by-design principles and proper code review processes that should identify and eliminate backdoor functionality during development phases. Organizations should also consider implementing network access controls and endpoint detection systems that can identify unauthorized command execution attempts on network devices, as this vulnerability operates outside normal operational parameters and can be difficult to detect through conventional security measures.