CVE-2020-3485 in Vision Dynamic Signage Director
Summary
by MITRE
A vulnerability in the role-based access control (RBAC) functionality of the web management software of Cisco Vision Dynamic Signage Director could allow an authenticated, remote attacker to access resources that they should not be able to access and perform actions that they should not be able to perform. The vulnerability exists because the web management software does not properly handle RBAC. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to view and delete certain screen content on the system that the attacker would not normally have privileges to access.
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Analysis
by VulDB Data Team • 11/10/2020
The vulnerability identified as CVE-2020-3485 resides within the role-based access control mechanisms of Cisco Vision Dynamic Signage Director web management software, representing a critical authorization flaw that undermines the fundamental security posture of the affected system. This weakness specifically targets the RBAC implementation, which is designed to enforce access controls based on user roles and permissions, yet fails to properly validate access requests. The vulnerability stems from inadequate input validation and access control enforcement within the web application layer, creating a path for unauthorized privilege escalation that directly violates the principle of least privilege. The flaw manifests when the system processes HTTP requests without sufficient validation of user permissions, allowing authenticated attackers to bypass intended access restrictions.
The technical exploitation of this vulnerability requires an authenticated attacker to craft and send specifically designed HTTP requests to the affected Cisco Vision Dynamic Signage Director device. This attack vector aligns with common web application exploitation techniques where improper access control validation leads to privilege escalation. The vulnerability is classified under CWE-285, which addresses improper authorization issues in software systems, and demonstrates how insufficient access control mechanisms can enable attackers to perform unauthorized actions. The attacker can leverage this flaw to access and manipulate screen content that should be restricted to specific user roles, including the ability to view and delete content that normally requires elevated privileges. The attack requires network access to the device's web management interface, making it particularly concerning for systems that are exposed to untrusted networks.
The operational impact of CVE-2020-3485 extends beyond simple unauthorized access, as it provides attackers with the capability to modify and delete critical signage content, potentially causing significant disruption to information dissemination systems. Organizations relying on Cisco Vision Dynamic Signage Director for digital signage management face risks including content tampering, unauthorized information disclosure, and potential service disruption. The vulnerability affects the integrity and availability of the signage content management system, which could be particularly damaging in enterprise environments where digital signage serves critical business functions such as emergency notifications, corporate communications, or customer information displays. This flaw represents a direct violation of the security triad, compromising both confidentiality and integrity of the system's content management capabilities.
Mitigation strategies for this vulnerability should include immediate deployment of Cisco's security patches and updates, which address the underlying RBAC implementation flaws. Network segmentation and access control measures should be implemented to limit exposure of the affected devices to untrusted networks, while monitoring for unusual access patterns or unauthorized content modifications. The principle of least privilege should be enforced more strictly, ensuring that user accounts have minimal necessary permissions to perform their functions. Additionally, organizations should conduct comprehensive access control reviews and implement network-based intrusion detection systems to monitor for exploitation attempts. The vulnerability highlights the importance of proper access control implementation and serves as a reminder that even authenticated access control mechanisms can be compromised when insufficient validation is performed at the application layer. This case study emphasizes the critical need for regular security assessments of web application components and the importance of maintaining up-to-date security patches across all enterprise systems.