CVE-2021-1176 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-2021-1176 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 with embedded operating systems that provide web administration capabilities, making them accessible through standard HTTP/HTTPS protocols. The vulnerability stems from insufficient input validation mechanisms within the web interface components that process user-supplied data. This weakness creates an attack surface where maliciously crafted HTTP requests can be processed without proper sanitization or verification, potentially leading to severe system compromise. The affected devices are commonly deployed in small business environments where network administrators rely on these web interfaces for routine configuration management and monitoring tasks.
The technical exploitation of this vulnerability involves sending specifically crafted HTTP requests that manipulate input fields within the web interface. When the affected device processes these malformed requests, the improper input validation allows malicious data to bypass security checks and execute within the context of the underlying operating system. This vulnerability maps directly to CWE-20, which describes "Improper Input Validation" and represents one of the most fundamental security weaknesses in software development. The attack requires authentication since valid administrator credentials must be present to access the web management interface, making this a privilege escalation vulnerability rather than a purely remote exploit. The authentication requirement means that attackers must first obtain administrative credentials through other means such as credential theft, default password exploitation, or social engineering attacks.
The operational impact of these vulnerabilities extends beyond simple code execution to include potential denial of service conditions that can disrupt business operations. When exploited successfully, attackers can execute arbitrary code with root privileges, effectively providing complete control over the device's operating system. This level of access allows attackers to modify network configurations, establish persistent backdoors, exfiltrate sensitive data, or use the compromised device as a pivot point for further attacks within the network. The device reload functionality creates a denial of service scenario that can interrupt network connectivity for extended periods, particularly problematic in environments where these routers serve as primary network gateways. The lack of available software updates for these devices leaves organizations vulnerable to exploitation without any official remediation path, creating a persistent security risk that requires alternative mitigation strategies.
Organizations affected by CVE-2021-1176 should implement immediate network segmentation to isolate these vulnerable devices from critical network segments. Network access control measures including firewall rules and access lists should be configured to restrict access to the web management interfaces to only trusted administrative workstations. Regular credential rotation and strong authentication mechanisms including multi-factor authentication should be enforced to reduce the likelihood of unauthorized access. Monitoring network traffic for suspicious HTTP request patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Security teams should also consider implementing network behavior analysis tools to detect anomalous activity that might indicate successful exploitation attempts. The vulnerability's mapping to ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1068 for "Exploitation for Privilege Escalation" indicates that attackers may leverage these capabilities to establish persistence and escalate their privileges within the compromised network environment.