CVE-2021-1186 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 vulnerability identified as CVE-2021-1186 affects Cisco Small Business routers including RV110W, RV130, RV130W, and RV215W models, presenting a critical security risk through their web-based management interfaces. These devices operate within small business environments where network security is paramount, yet they suffer from fundamental input validation flaws that create pathways for malicious exploitation. The vulnerability stems from inadequate sanitization of user-supplied data within the web interface components, allowing attackers to manipulate input fields and potentially gain unauthorized system access. This weakness represents a classic example of insufficient input validation, a common vector for privilege escalation and remote code execution attacks.
The technical exploitation of CVE-2021-1186 occurs through crafted HTTP requests sent to the affected router's web management interface. Attackers with valid administrator credentials can leverage this vulnerability to execute arbitrary code with root privileges on the underlying operating system, effectively compromising the entire device. The flaw manifests as improper validation of user-supplied input, which aligns with CWE-20 - Improper Input Validation, a fundamental weakness that enables attackers to inject malicious payloads into application interfaces. This vulnerability type is particularly dangerous because it operates at the application layer where administrative functions are exposed, allowing attackers to bypass normal access controls and gain system-level privileges.
The operational impact of this vulnerability extends beyond simple code execution to include potential denial of service conditions through device reloads. When exploited successfully, the vulnerability can cause the affected router to unexpectedly restart, disrupting network connectivity for all connected devices and potentially leading to extended downtime for small business operations. This dual nature of the vulnerability - enabling both code execution and denial of service - makes it particularly attractive to threat actors seeking to either compromise network infrastructure or disrupt business operations. The requirement for valid administrator credentials to exploit these vulnerabilities does not mitigate the risk significantly, as credential theft remains a common attack vector in small business environments.
Organizations affected by CVE-2021-1186 should implement immediate mitigations while awaiting official patches from Cisco, though the vendor has not released software updates addressing these specific issues. Network segmentation and access control measures can help limit the attack surface, while monitoring for unusual network behavior and unauthorized administrative access attempts should be enhanced. The vulnerability demonstrates the importance of maintaining up-to-date firmware and security patches, particularly for network infrastructure devices that are often overlooked in security assessments. This weakness also aligns with ATT&CK technique T1059.007 - Command and Scripting Interpreter: Python, as attackers may attempt to execute malicious code through the compromised web interface, and T1489 - Service Stop, as the denial of service component could be used to disrupt network services. Given the lack of available patches, organizations should consider network monitoring solutions that can detect anomalous HTTP traffic patterns and implement strict access controls to limit administrative access to these critical network devices.