CVE-2021-1188 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 • 02/13/2021
The CVE-2021-1188 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 gateways in small business environments, making them attractive targets for cybercriminals seeking persistent access to corporate networks. The vulnerability stems from insufficient input validation mechanisms within the web interface, creating pathways for malicious actors to manipulate the system through carefully crafted HTTP requests that bypass normal authentication procedures.
The technical exploitation of this vulnerability involves improper validation of user-supplied input, which aligns with CWE-20 - Improper Input Validation, a fundamental weakness that has been consistently identified as a primary vector for web application attacks. When an authenticated attacker sends malicious HTTP requests to the affected device, the system fails to properly sanitize or validate the input parameters, allowing arbitrary code execution as the root user on the underlying operating system. This privilege escalation capability represents a severe security risk as it provides complete control over the router's functionality, including network traffic interception, firewall rule modification, and potential lateral movement within the network infrastructure.
The operational impact of these vulnerabilities extends beyond simple code execution to include denial of service conditions through device reloads, which can disrupt business operations and create network outages. The requirement for valid administrator credentials to exploit these vulnerabilities means that attackers must first compromise administrative accounts through methods such as credential brute force attacks, password spraying, or social engineering techniques, but once achieved, the attacker gains complete administrative control over the network gateway. This scenario represents a classic privilege escalation attack pattern that aligns with ATT&CK technique T1068 - Exploitation for Privilege Escalation, where initial access is leveraged to gain elevated system privileges.
Organizations affected by CVE-2021-1188 face significant operational risks as these routers serve as critical network infrastructure components that control network access and traffic flow. The lack of available software updates from Cisco creates an immediate security gap that requires alternative mitigation strategies. Network segmentation approaches should be implemented to isolate these vulnerable devices from critical network segments, while monitoring systems should be enhanced to detect unusual HTTP traffic patterns or unauthorized access attempts. Additionally, administrative credential rotation and implementation of multi-factor authentication where possible can help reduce the attack surface, though the fundamental input validation flaws remain unaddressed without official patches. The vulnerability demonstrates the importance of maintaining up-to-date firmware and the risks associated with legacy device support in enterprise environments.