CVE-2020-3521 in Data Center Network Manager
Summary
by MITRE
A vulnerability in a specific REST API of Cisco Data Center Network Manager (DCNM) Software could allow an authenticated, remote attacker to conduct directory traversal attacks on an affected device. The vulnerability is due to insufficient validation of user-supplied input to the API. An attacker with a low-privileged account could exploit this vulnerability by sending a crafted request to the API. A successful exploit could allow the attacker to read arbitrary files on the affected system.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/10/2020
The vulnerability identified as CVE-2020-3521 resides within Cisco Data Center Network Manager software, specifically targeting its REST API implementation. This critical security flaw stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing. The affected system operates under the assumption that legitimate requests will not contain maliciously crafted parameters, creating an exploitable gap in the application's defensive architecture. The vulnerability affects Cisco DCNM versions prior to 10.3.1, making it particularly concerning given the widespread deployment of this network management solution across enterprise data center environments.
The technical exploitation of this vulnerability relies on directory traversal attack vectors that leverage insufficient input validation within the REST API endpoints. When an authenticated user submits a maliciously crafted request containing directory traversal sequences such as ../ or ..\, the system fails to properly validate these inputs before processing file operations. This allows an attacker to manipulate file path resolution mechanisms and access files outside of the intended directory structure. The vulnerability is classified under CWE-22, which specifically addresses directory traversal or path traversal flaws in software systems. The attack requires minimal privileges since the exploit can be executed by users with low-privileged accounts, making it particularly dangerous in environments where privilege escalation is not properly enforced.
Operational impact of this vulnerability extends beyond simple unauthorized file access, as it provides attackers with the capability to extract sensitive configuration data, authentication credentials, and system information that could facilitate further exploitation. The remote nature of the attack means that adversaries do not require physical access to the affected system, enabling them to conduct reconnaissance and data exfiltration from external network locations. This vulnerability directly impacts the confidentiality and integrity of network management data, potentially exposing critical infrastructure information that could be used to plan more sophisticated attacks. The exploitation could lead to complete system compromise if sensitive files containing administrative credentials or encryption keys are accessible through the directory traversal mechanism, representing a significant threat to enterprise network security posture.
Organizations affected by CVE-2020-3521 should prioritize immediate remediation through official Cisco security advisories and software updates. The recommended mitigation strategy involves upgrading to Cisco DCNM version 10.3.1 or later, which includes proper input validation controls and sanitization mechanisms for REST API endpoints. Network administrators should also implement additional security controls such as API request rate limiting, enhanced monitoring of REST API access patterns, and regular security assessments of network management interfaces. The vulnerability demonstrates the importance of input validation in web applications and highlights the necessity of following secure coding practices that align with OWASP Top Ten security requirements. Security teams should also consider implementing network segmentation and access control measures to limit the potential impact of successful exploitation attempts, particularly in environments where the DCNM system serves as a critical network management component.