CVE-2020-24579 in DSL-2888A
Summary
by MITRE • 12/23/2020
An issue was discovered on D-Link DSL-2888A devices with firmware prior to AU_2.31_V1.1.47ae55. An unauthenticated attacker could bypass authentication to access authenticated pages and functionality.
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Analysis
by VulDB Data Team • 12/23/2020
The vulnerability identified in D-Link DSL-2888A devices represents a critical authentication bypass flaw that undermines the fundamental security model of the affected network infrastructure equipment. This issue affects firmware versions prior to AU_2.31_V1.1.47ae55 and exposes the device to unauthorized access from unauthenticated attackers who can gain access to authenticated pages and functionality without proper credentials. The vulnerability stems from inadequate session management and authentication validation mechanisms within the web interface implementation.
The technical flaw manifests as a failure in the authentication checkpoint system where the device does not properly verify user credentials before granting access to administrative functions. This allows an attacker to directly access protected URLs and interfaces that should only be available to authenticated administrators. The vulnerability falls under CWE-287 which specifically addresses improper authentication issues, and aligns with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting through network services. The flaw essentially creates a backdoor path through the device's security controls, enabling attackers to perform administrative actions such as configuration changes, firmware updates, or access to sensitive network information.
The operational impact of this vulnerability is severe as it allows an unauthenticated attacker to assume administrative privileges on the DSL-2888A router. This compromise enables potential attackers to modify network settings, create backdoors, monitor traffic, or redirect network requests to malicious endpoints. The affected device serves as a gateway for home and small office networks, making the impact significantly broader than a single device compromise. An attacker could leverage this vulnerability to establish persistent access points within the network, potentially leading to data exfiltration or further lateral movement throughout the connected infrastructure.
Mitigation strategies should immediately involve firmware updates to version AU_2.31_V1.1.47ae55 or later, which contain patches addressing the authentication bypass mechanism. Network administrators should also implement additional security controls including disabling unnecessary web interfaces, restricting access through firewall rules, and implementing network segmentation to limit the potential impact of any successful compromise. The device should be configured with strong default credentials that are changed immediately upon initial setup, and regular security audits should be performed to ensure no unauthorized changes have occurred. Organizations should also consider network monitoring solutions that can detect unusual traffic patterns or access attempts to administrative interfaces that may indicate exploitation attempts.