CVE-2017-8771 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"). The attacker can make a user that is connected to the repeater click on a malicious link that will log into the telnet and will infect the device with malicious code.
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Analysis
by VulDB Data Team • 11/18/2019
The CVE-2017-8771 vulnerability affects BE126 WIFI repeater version 1.0 devices and represents a critical security flaw stemming from improper authentication mechanisms and default credential configurations. This vulnerability exposes devices to unauthorized access through the telnet service, which remains enabled and accessible by default. The device employs weak default credentials with the username "root" and password "root" that are widely known and easily exploitable by threat actors. The vulnerability aligns with CWE-798, which addresses the use of hard-coded credentials, and CWE-259, covering weak password policies. The security implications extend beyond simple unauthorized access as this vulnerability demonstrates a classic example of how default configurations can create persistent security risks in networked devices.
The technical exploitation of this vulnerability occurs through a combination of default service enablement and predictable credential usage. Attackers can directly connect to the telnet service without requiring additional reconnaissance or complex exploitation techniques. Once authenticated, the attacker gains root-level access to the device, enabling complete control over the network repeater's operations. The attack vector described involves social engineering through malicious links that, when clicked by connected users, automatically establish telnet connections to the device. This approach leverages the device's default open state and weak authentication to achieve persistent access without requiring sophisticated exploitation methods. The vulnerability demonstrates a fundamental security misconfiguration that violates the principle of least privilege and proper access control implementation.
The operational impact of CVE-2017-8771 extends beyond immediate device compromise to potentially enable broader network infiltration and persistent threats. Compromised repeaters can serve as footholds for attackers to establish command and control channels, conduct man-in-the-middle attacks, or use the device as a launch point for further network exploration. The vulnerability creates a persistent backdoor that remains active as long as the device operates with default settings, making it particularly dangerous for enterprise environments where multiple devices may be similarly configured. Network administrators face significant challenges in identifying and securing these devices, as the default open telnet service often goes unnoticed in routine security assessments. This vulnerability aligns with ATT&CK technique T1072, which covers software deployment methods, and T1021.001, covering remote services.
Mitigation strategies for CVE-2017-8771 must address both immediate remediation and long-term security hardening measures. The primary recommendation involves disabling or securing the telnet service through configuration changes, particularly by changing default credentials to strong, unique passwords for each device. Network segmentation and firewall rules should be implemented to restrict access to telnet ports from unauthorized networks. Regular security audits should include verification of default service states and credential configurations across all networked devices. Device firmware updates should be applied when available to address known vulnerabilities. Additionally, implementing network monitoring solutions can help detect unauthorized telnet access attempts and alert security teams to potential exploitation. The vulnerability underscores the importance of network security hygiene and the critical need for device hardening practices that align with industry standards such as NIST SP 800-125 and ISO 27001 requirements for secure device configuration management.