CVE-2017-8772 in WiFI Repeater
Summary
by MITRE
On BE126 WIFI repeater 1.0 devices, an attacker can log into telnet (which is open by default) with default credentials as root (username:"root" password:"root") and can: 1. Read the entire file system; 2. Write to the file system; or 3. Execute any code that attacker desires (malicious or not).
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Analysis
by VulDB Data Team • 11/18/2019
The CVE-2017-8772 vulnerability affects BE126 WIFI repeater version 1.0 devices and represents a critical security flaw stemming from inadequate authentication mechanisms and default credential configurations. This vulnerability exposes devices to remote exploitation through telnet services that remain enabled by default, creating an attack surface that allows unauthorized access without requiring additional reconnaissance or privilege escalation techniques. The device's default configuration includes hardcoded credentials with the username "root" and password "root" which persist across all affected units, making this vulnerability particularly dangerous as it requires no specialized knowledge to exploit.
The technical flaw manifests through the lack of proper access controls and authentication enforcement within the device's network services. Telnet protocol implementation on these devices fails to implement adequate security measures including account lockout mechanisms, secure authentication protocols, or proper credential management. This vulnerability directly maps to CWE-798, which addresses the use of hard-coded credentials, and CWE-255, which covers insecure authentication mechanisms. The exposed telnet service operates with minimal security considerations, allowing attackers to establish connections using default credentials without any additional security barriers or monitoring systems.
The operational impact of this vulnerability is severe and encompasses complete system compromise capabilities that enable attackers to execute arbitrary code with root privileges. Successful exploitation allows attackers to read the entire file system, write to system files, and execute malicious code, effectively providing full control over the device's functionality and data. This level of access enables attackers to modify device configurations, install backdoors, exfiltrate sensitive information, or use the compromised device as a pivot point for attacking other networked systems. The vulnerability's impact aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as attackers can leverage this initial access to gain elevated privileges and expand their control.
Mitigation strategies should focus on immediate credential changes and service disablement. Organizations must immediately change default credentials to strong, unique passwords for all affected devices and disable unnecessary services including telnet. Network segmentation and firewall rules should be implemented to restrict access to device management interfaces to authorized personnel only. Regular security audits and vulnerability assessments should be conducted to identify and remediate similar issues across network infrastructure. The device manufacturer should implement secure default configurations that disable unnecessary services, enforce strong authentication mechanisms, and provide clear security guidelines for device deployment. Additionally, network monitoring should be enhanced to detect unauthorized access attempts and anomalous network behavior that may indicate exploitation attempts.