CVE-2021-1183 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-2021-1183 affects Cisco Small Business routers including RV110W, RV130, RV130W, and RV215W models, representing a critical security flaw in their web-based management interfaces. This issue stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied data before processing within the router's operating system. The vulnerability classification aligns with CWE-20, which describes improper input validation as a fundamental weakness in software design that enables various attack vectors including code execution and denial of service conditions.
The technical exploitation of this vulnerability requires an authenticated attacker who possesses valid administrator credentials for the affected device, as demonstrated by the attack vector analysis. Attackers can leverage this flaw by crafting specially designed HTTP requests that bypass normal input validation checks within the web interface. These malicious requests exploit the underlying operating system's failure to properly validate and sanitize incoming data, creating a path for arbitrary code execution with root privileges. The vulnerability's impact is particularly severe because it allows attackers to gain complete control over the device's operating system, enabling them to execute commands with the highest level of system privileges and potentially establish persistent access to the network infrastructure.
From an operational perspective, the exploitation of CVE-2021-1183 can result in two primary consequences that significantly impact network security and availability. The first scenario involves arbitrary code execution as the root user, which provides attackers with complete administrative control over the router, potentially allowing them to modify network configurations, establish backdoors, or use the device as a pivot point for further attacks within the network. The second consequence manifests as unexpected device restarts or reloads, creating a denial of service condition that disrupts network connectivity and may require manual intervention to restore normal operations. This dual nature of the vulnerability makes it particularly dangerous as it can be used for both persistent infiltration and disruptive attacks.
The vulnerability's characteristics align with ATT&CK technique T1059, which covers command and scripting interpreter, as attackers can execute arbitrary commands through the compromised interface. Additionally, the lack of available software updates from Cisco creates a persistent risk for affected organizations, as they cannot remediate the issue through standard patch management processes. Organizations using these routers should implement network segmentation, monitor for unusual HTTP traffic patterns, and consider disabling the web-based management interface when possible. The vulnerability also highlights the importance of principle of least privilege in network device management, as the requirement for valid administrator credentials, while providing some protection, does not prevent attackers who have already compromised administrative accounts from exploiting this flaw.