CVE-2019-9124 in DIR-878
Summary
by MITRE
An issue was discovered on D-Link DIR-878 1.12B01 devices. At the /HNAP1 URI, an attacker can log in with a blank password.
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Analysis
by VulDB Data Team • 07/19/2023
The vulnerability identified as CVE-2019-9124 affects D-Link DIR-878 routers running firmware version 1.12B01 and potentially other affected models within the DIR-878 series. This security flaw resides within the device's web-based management interface at the /HNAP1 URI endpoint, which is part of the Home Network Administration Protocol implementation. The issue represents a critical authentication bypass vulnerability that allows unauthorized remote access to the device's administrative functions without proper credential validation.
The technical flaw manifests as a weak authentication mechanism that fails to properly validate login credentials when accessing the HNAP1 interface. Specifically, the system accepts blank password submissions as valid authentication attempts, effectively creating a backdoor access method that bypasses normal user authentication procedures. This vulnerability stems from inadequate input validation and authentication logic within the router's web server implementation, allowing any remote attacker to gain administrative privileges simply by submitting an empty password field during the login process. The flaw demonstrates poor security design practices and violates fundamental authentication security principles.
The operational impact of this vulnerability is severe and far-reaching for affected users. An attacker who discovers this vulnerability can gain complete administrative control over the affected router, enabling them to modify network configurations, change DNS settings, disable security features, access network traffic, and potentially establish persistent backdoors. The vulnerability affects the router's core network security functions, as it allows unauthorized access to the device's management interface where all critical network parameters are configured. This includes the ability to modify firewall settings, change administrator passwords, configure port forwarding rules, and access sensitive network information that could facilitate further attacks on the local network.
From a cybersecurity perspective, this vulnerability aligns with CWE-287, which addresses improper authentication issues, and represents a classic example of weak authentication mechanisms that fail to properly validate user credentials. The attack vector falls under the ATT&CK framework's privilege escalation techniques, specifically targeting the T1068 - Exploitation for Privilege Escalation tactic. The vulnerability also maps to T1071.004 - Application Layer Protocol: DNS, as attackers could potentially use the compromised device to redirect DNS traffic or establish command and control channels. Additionally, this flaw contributes to the broader category of T1566 - Phishing, as it could enable attackers to create more sophisticated social engineering campaigns by compromising network infrastructure.
Mitigation strategies for this vulnerability should include immediate firmware updates from D-Link, which would address the authentication bypass issue through proper credential validation. Network administrators should also implement additional security measures such as disabling remote management access entirely when not required, restricting access to specific IP addresses, and implementing strong network segmentation to limit the impact of potential compromises. Regular security audits and network monitoring should be conducted to detect unauthorized access attempts, while multi-factor authentication mechanisms should be considered for critical network infrastructure. Organizations should also maintain up-to-date vulnerability scanning procedures to identify similar authentication weaknesses in other network devices and ensure proper network access controls are in place to minimize the attack surface.