CVE-2021-1602 in RV160
Summary
by MITRE • 08/05/2021
A vulnerability in the web-based management interface of Cisco Small Business RV160, RV160W, RV260, RV260P, and RV260W VPN Routers could allow an unauthenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. This vulnerability is due to insufficient user input validation. An attacker could exploit this vulnerability by sending a crafted request to the web-based management interface. A successful exploit could allow the attacker to execute arbitrary commands on an affected device using root-level privileges. Due to the nature of the vulnerability, only commands without parameters can be executed.
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Analysis
by VulDB Data Team • 08/08/2021
This vulnerability resides within the web-based management interface of Cisco Small Business series VPN routers including RV160, RV160W, RV260, RV260P, and RV260W models. The flaw represents a critical security weakness that enables unauthenticated remote command execution, fundamentally compromising the device's integrity and security posture. The vulnerability stems from inadequate input validation mechanisms within the web interface, creating a pathway for malicious actors to inject and execute arbitrary commands on the underlying operating system. This type of vulnerability falls under the CWE-20 category, specifically addressing improper input validation, which is a foundational weakness in software security architecture. The attack vector requires only a crafted HTTP request to be sent to the vulnerable web interface, making exploitation relatively straightforward and accessible to threat actors without specialized technical knowledge.
The technical exploitation of this vulnerability occurs through the manipulation of user input parameters within the web interface. When an attacker sends a specially crafted request containing malicious command sequences, the insufficient validation allows these commands to be passed directly to the operating system without proper sanitization or authorization checks. The vulnerability specifically affects the command execution functionality within the router's web management interface, where user-supplied parameters are processed without adequate security controls. The exploitation results in root-level privilege execution, granting attackers complete control over the device's operating system and all its functionalities. This includes access to network configuration, user credentials, and potential lateral movement capabilities within the network. The limitation that only commands without parameters can be executed suggests that the vulnerability may be mitigated through proper parameter handling or that the attack surface is constrained by the implementation details of the vulnerable code.
The operational impact of this vulnerability extends far beyond the immediate compromise of individual devices, creating significant risks for network security and business continuity. An unauthenticated remote attacker can gain complete administrative control over affected routers, potentially leading to complete network compromise, data exfiltration, and disruption of critical network services. The vulnerability affects small business networks where these routers are commonly deployed, often without proper security monitoring or network segmentation. This creates a dangerous environment where attackers can establish persistent access points, redirect network traffic, or use the compromised devices as launch points for attacks against other network resources. The vulnerability's presence in multiple router models within the Cisco Small Business line amplifies the potential impact, affecting a wide range of organizations that rely on these devices for network connectivity and security. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) as potential initial access vectors, while T1078 (Valid Accounts) and T1021.001 (Remote Services: Remote Desktop Protocol) represent possible exploitation techniques.
Organizations should implement immediate mitigations including applying the latest firmware updates from Cisco, which address the input validation weaknesses in the web interface. Network segmentation and firewall rules should be implemented to restrict access to the router management interfaces, limiting access to trusted administrative networks only. Additional protective measures include disabling unnecessary web management services when not required, implementing strong authentication mechanisms, and deploying network monitoring solutions to detect anomalous command execution patterns. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in other network components. The vulnerability highlights the importance of secure coding practices and input validation in web applications, particularly those handling administrative functions. Organizations should also consider implementing network access control lists to prevent unauthorized access to router management interfaces and establish incident response procedures for rapid detection and remediation of such vulnerabilities. Cisco has released security advisories and patches addressing this vulnerability, emphasizing the critical nature of timely patch management for maintaining network security.