CVE-2021-1171 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-2021-1171 affects Cisco Small Business routers including models RV110W, RV130, RV130W, and RV215W, representing a critical security flaw in the web-based management interface of these network devices. This vulnerability stems from improper input validation mechanisms that fail to adequately sanitize user-supplied data before processing within the router's web interface. The flaw creates a path for authenticated remote code execution and denial of service conditions, making it particularly dangerous for small business network environments where these devices are commonly deployed.
The technical exploitation of this vulnerability occurs through crafted HTTP requests sent to the affected devices, leveraging the insufficient input validation to inject malicious payloads into the system. The vulnerability's classification aligns with CWE-20, which addresses "Improper Input Validation" in software systems, specifically targeting the web interface components of these routers. Attackers must possess valid administrator credentials to exploit these flaws, but once authenticated, they can execute arbitrary code with root privileges on the underlying operating system, effectively compromising the entire device. This privilege escalation capability allows attackers to gain complete control over the router's functions and potentially use it as a foothold for broader network attacks.
The operational impact of CVE-2021-1171 extends beyond simple code execution to include potential device instability and denial of service conditions. When exploited successfully, the vulnerabilities can cause the affected routers to reload unexpectedly, disrupting network connectivity and potentially creating service outages for businesses relying on these devices. This behavior manifests through the exploitation of the improper input validation to trigger system-level failures that result in device reboot cycles, which can be particularly disruptive in small business environments where network uptime is critical for operations. The lack of available software updates from Cisco for these specific vulnerabilities compounds the risk, leaving affected organizations without official remediation paths.
Organizations affected by this vulnerability should implement immediate network segmentation to limit access to these devices, restrict administrative access to only necessary personnel, and consider deploying network monitoring solutions to detect anomalous HTTP traffic patterns that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1059.007 for command and script interpreter, specifically targeting the execution of arbitrary code through web-based interfaces. Security teams should also consider implementing web application firewalls to filter potentially malicious HTTP requests and establish baseline network behavior to detect unauthorized device reboots or unusual traffic patterns that could indicate exploitation attempts.