CVE-2021-1147 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 inject arbitrary commands that are executed with root privileges. 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 a targeted device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system. To exploit these vulnerabilities, an attacker would need to have valid administrator credentials on an 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-2021-1147 represents a critical command injection flaw in Cisco Small Business routers including the RV110W, RV130, RV130W, and RV215W models. This issue stems from inadequate input validation within the web-based management interface, creating a pathway for authenticated remote attackers to execute malicious commands with root privileges. The vulnerability specifically affects the authentication mechanism and input sanitization processes that govern how user-supplied data is processed within the device's web interface. Attackers exploiting this weakness can craft specially formatted HTTP requests that bypass normal security controls and gain unauthorized access to the underlying operating system with administrative privileges.
The technical exploitation of CVE-2021-1147 follows a well-established pattern of command injection attacks where user input is improperly validated and directly incorporated into system commands without adequate sanitization. This flaw falls under CWE-77 which categorizes improper neutralization of special elements used in commands, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter. The vulnerability requires an attacker to possess valid administrator credentials to initiate exploitation, making it a privilege escalation issue rather than a simple remote code execution vulnerability. However, the impact remains severe as the authenticated attacker can leverage this flaw to execute arbitrary commands with root privileges on the target device's operating system, effectively compromising the entire router infrastructure.
The operational impact of this vulnerability extends beyond simple unauthorized access as it allows attackers to completely compromise the affected router devices. Once exploited, attackers can modify router configurations, redirect network traffic, establish backdoors, or use the compromised devices as launching points for further attacks within the network. The affected devices operate as network gateways and security boundaries, making their compromise particularly dangerous for organizations relying on these small business routers. The lack of available software updates from Cisco at the time of discovery left affected organizations with limited options for remediation, forcing them to implement workarounds or network segmentation strategies to mitigate the risk.
Organizations affected by CVE-2021-1147 should implement immediate defensive measures including network segmentation to isolate affected devices, enforcing strict access controls, and monitoring for suspicious network activity that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of input validation and proper authentication mechanisms in network device management interfaces. Security teams should conduct thorough assessments of their network infrastructure to identify all affected devices and implement layered security controls. Additionally, organizations should consider implementing network monitoring solutions that can detect anomalous HTTP request patterns or unusual command execution attempts that might indicate exploitation of this vulnerability. The absence of official patches from Cisco highlights the necessity for organizations to maintain robust security monitoring capabilities and incident response procedures to address zero-day vulnerabilities effectively.