CVE-2020-29323 in DIR-885L-MFC
Summary
by MITRE • 06/05/2021
The D-link router DIR-885L-MFC 1.15b02, v1.21b05 is vulnerable to credentials disclosure in telnet service through decompilation of firmware, that allows an unauthenticated attacker to gain access to the firmware and to extract sensitive data.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/10/2021
The vulnerability identified as CVE-2020-29323 affects D-Link DIR-885L-MFC routers running firmware versions 1.15b02 and 1.21b05, representing a critical security flaw in the telnet service implementation. This issue stems from inadequate credential handling within the router's firmware, creating a pathway for unauthorized access through firmware decompilation techniques that expose sensitive authentication information.
The technical flaw manifests through the exposure of telnet credentials within the router's firmware binary, which can be reverse-engineered using standard decompilation tools and techniques. This weakness allows attackers to extract hardcoded administrative credentials without requiring any prior authentication, effectively bypassing the router's security mechanisms. The vulnerability is classified under CWE-798 as the use of hard-coded credentials, while also aligning with CWE-312 which addresses the exposure of sensitive information through cleartext storage. The attack vector involves firmware analysis and decompilation processes that reveal stored credentials, making this an information disclosure vulnerability with significant operational impact.
The operational impact of this vulnerability extends beyond simple credential theft, as it provides attackers with full administrative access to the affected routers. This access enables unauthorized modification of network configurations, implementation of man-in-the-middle attacks, and potential lateral movement within the network infrastructure. The vulnerability affects network security posture significantly, as it allows attackers to compromise network access control, modify routing tables, and potentially establish persistent backdoors. This issue directly aligns with ATT&CK technique T1078.004 for Valid Accounts and T1566.001 for Phishing, as it enables unauthorized access through legitimate administrative credentials and provides a method for initial compromise of network infrastructure.
Mitigation strategies for CVE-2020-29323 should prioritize immediate firmware updates from D-Link to address the hardcoded credential issue, while network administrators should disable unnecessary services including telnet and implement strong network segmentation. The implementation of network monitoring solutions to detect unauthorized access attempts and credential harvesting activities provides additional defense layers. Regular firmware audits and security assessments of network infrastructure help identify similar vulnerabilities across the organization's device inventory, while mandatory credential rotation policies ensure that even if such vulnerabilities are exploited, the impact is minimized through short credential lifecycles and robust authentication mechanisms.