CVE-2020-3520 in Data Center Network Manager
Summary
by MITRE
A vulnerability in Cisco Data Center Network Manager (DCNM) Software could allow an authenticated, local attacker to obtain confidential information from an affected device. The vulnerability is due to insufficient protection of confidential information on an affected device. An attacker at any privilege level could exploit this vulnerability by accessing local filesystems and extracting sensitive information from them. A successful exploit could allow the attacker to view sensitive data, which they could use to elevate their privilege.
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Analysis
by VulDB Data Team • 11/10/2020
The vulnerability identified as CVE-2020-3520 affects Cisco Data Center Network Manager software, presenting a significant security risk through inadequate protection of confidential information within the system. This weakness specifically targets the local filesystems of affected devices, creating an avenue for authenticated attackers to extract sensitive data that could compromise system integrity and security posture. The vulnerability exists within the software's handling of confidential information storage and access controls, making it particularly dangerous as it allows attackers to escalate their privileges through the exposure of sensitive data.
This security flaw represents a critical failure in information protection mechanisms that should prevent unauthorized access to sensitive system data. The vulnerability stems from insufficient safeguards that should normally protect confidential information stored on the local filesystems of DCNM devices. Attackers with any level of authentication can exploit this weakness by directly accessing the local filesystems and extracting sensitive information that would typically remain protected. The design flaw allows for the exposure of data that could include authentication credentials, configuration details, or other sensitive system information that could be leveraged for further attacks.
The operational impact of this vulnerability extends beyond simple data exposure, as the extracted sensitive information can be used to elevate attacker privileges within the system. This creates a dangerous escalation path where initial access to local filesystems can lead to broader system compromise. The vulnerability affects the fundamental security model of the DCNM software by failing to maintain proper separation between different privilege levels and sensitive data storage. Organizations relying on DCNM for data center network management face significant risk of unauthorized access and potential system takeover.
From a cybersecurity perspective, this vulnerability aligns with CWE-312 (Cleartext Storage of Sensitive Information) and CWE-284 (Improper Access Control) categories, demonstrating poor implementation of information protection and access control mechanisms. The attack pattern follows typical privilege escalation techniques documented in the MITRE ATT&CK framework under the T1068 (Local Port Forwarding) and T1548.001 (Abuse Elevation Control Mechanism) techniques. The vulnerability represents a fundamental breakdown in the principle of least privilege and proper data classification, where sensitive information should remain protected even from authenticated users with legitimate access rights.
Organizations should implement immediate mitigations including regular security assessments of DCNM installations, enhanced access controls for local filesystem access, and comprehensive monitoring of filesystem access patterns. The recommended approach involves applying Cisco's security patches and updates as soon as they become available, implementing network segmentation to limit access to DCNM systems, and conducting regular audits of filesystem permissions and access logs. Additionally, organizations should establish strict policies governing local filesystem access and implement automated monitoring systems to detect unauthorized access attempts to sensitive data repositories.