CVE-2021-1215 in Small Business
Summary
by MITRE • 01/14/2021
Multiple vulnerabilities in the web-based management interface of Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers could allow an authenticated, remote attacker to execute arbitrary code or cause an affected device to restart unexpectedly. The vulnerabilities are due to improper validation of user-supplied input in the web-based management interface. An attacker could exploit these vulnerabilities by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a denial of service (DoS) condition. To exploit these vulnerabilities, an attacker would need to have valid administrator credentials on the affected device. Cisco has not released software updates that address these vulnerabilities.
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Analysis
by VulDB Data Team • 02/14/2021
The CVE-2021-1215 vulnerability affects Cisco Small Business routers including RV110W, RV130, RV130W, and RV215W models, representing a critical security flaw in their web-based management interfaces. These devices operate as network infrastructure components that require administrative access for configuration and management, making them attractive targets for attackers seeking persistent network control. The vulnerability stems from inadequate input validation mechanisms within the web interface, creating a pathway for malicious exploitation through crafted HTTP requests that bypass normal security controls. This flaw demonstrates a fundamental weakness in the application's security architecture where user-supplied data is not properly sanitized before being processed by the underlying operating system.
The technical implementation of this vulnerability aligns with CWE-20, which describes improper input validation as a core weakness in software design. Attackers can leverage this flaw by crafting malicious HTTP requests containing specially formatted input that triggers buffer overflows or command injection behaviors within the router's web management interface. The exploitation requires valid administrator credentials, establishing a privilege escalation vector that transforms legitimate administrative access into full system compromise. This authentication requirement does not eliminate the threat, as compromised administrative credentials are a common attack surface in network environments where weak credential practices or credential theft occur through phishing, brute force attacks, or compromised endpoints.
The operational impact of CVE-2021-1215 extends beyond simple code execution to include potential denial of service conditions that can disrupt network operations for extended periods. When exploited successfully, the vulnerability allows attackers to execute arbitrary code with root privileges on the underlying operating system, providing complete control over the affected device and potentially enabling lateral movement throughout the network. The device reload functionality creates additional attack vectors for DoS conditions that can be used to maintain persistent disruption of network services, while the root-level code execution capability enables attackers to install backdoors, modify routing tables, or redirect network traffic to malicious endpoints. This vulnerability directly maps to ATT&CK technique T1059 for command and scripting interpreter and T1499 for network disruption, making it a particularly dangerous threat for enterprise networks.
Organizations must implement immediate mitigation strategies including network segmentation to isolate affected devices from critical infrastructure, enforcement of strong authentication controls with multi-factor authentication, and monitoring for unusual administrative access patterns. The lack of official software updates from Cisco for this vulnerability necessitates network administrators to consider alternative defensive measures such as deploying network intrusion detection systems to monitor for suspicious HTTP request patterns, implementing strict access controls for administrative interfaces, and conducting thorough credential audits to identify potential compromised accounts. Regular security assessments should focus on identifying all instances of these vulnerable router models within the network infrastructure to ensure comprehensive protection against exploitation attempts.