CVE-2020-3401 in SD-WAN vManage
Summary
by MITRE
A vulnerability in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to conduct path traversal attacks and obtain read access to sensitive files on an affected system. The vulnerability is due to insufficient validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request that contains directory traversal character sequences to the affected system. A successful exploit could allow the attacker to view arbitrary files on the affected system.
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Analysis
by VulDB Data Team • 11/04/2020
The vulnerability identified as CVE-2020-3401 affects the web-based management interface of Cisco SD-WAN vManage Software, representing a critical security flaw that enables authenticated remote attackers to execute path traversal attacks. This vulnerability specifically targets the software's insufficient validation of HTTP requests, creating a pathway for malicious actors to access sensitive system files. The affected Cisco SD-WAN vManage platform serves as a central management console for software-defined wide area networks, making it a prime target for attackers seeking to compromise network infrastructure. The vulnerability exists within the web interface's handling of user-supplied input, where proper sanitization and validation mechanisms fail to prevent malicious directory traversal sequences from being processed.
The technical exploitation of CVE-2020-3401 relies on the attacker sending crafted HTTP requests containing directory traversal character sequences such as ../ or ..\ that bypass input validation controls. When the vManage software processes these malformed requests, it fails to properly validate the user input before accessing the file system, allowing the attacker to navigate to arbitrary directories and read sensitive files. This weakness directly maps to CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal vulnerabilities. The vulnerability is particularly dangerous because it requires only authentication to the management interface, meaning that attackers who have gained valid credentials can leverage this flaw to escalate their access and extract confidential information from the system.
The operational impact of this vulnerability extends beyond simple file access, as the exposed files may contain sensitive configuration data, user credentials, system logs, or other confidential information that could be leveraged for further attacks. Attackers could potentially access system configuration files that reveal network topology, device credentials, or other sensitive operational data. The vulnerability affects the integrity and confidentiality of the entire SD-WAN management infrastructure, potentially allowing attackers to gain insights into network operations and plan more sophisticated attacks against the organization's network infrastructure. This type of vulnerability aligns with ATT&CK technique T1083, which covers discovering file and directory permissions, and T1566, which involves credential access through various means including exploitation of software vulnerabilities.
Organizations utilizing Cisco SD-WAN vManage software should implement immediate mitigations including applying the vendor-provided security patches and updates released to address this vulnerability. Network administrators should also consider implementing additional security controls such as restricting access to the management interface through network segmentation, implementing strict access controls, and monitoring for suspicious HTTP requests containing directory traversal sequences. The vulnerability demonstrates the importance of input validation and proper security controls in web applications, particularly those managing critical network infrastructure. Organizations should conduct comprehensive security assessments to identify similar vulnerabilities in other network management systems and implement robust security monitoring to detect and prevent exploitation attempts. The incident highlights the necessity of following security best practices including principle of least privilege, regular security updates, and continuous monitoring of network management interfaces for unauthorized access attempts.