CVE-2021-1212 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 • 02/14/2021
The vulnerability identified as CVE-2021-1212 affects Cisco Small Business routers including models RV110W, RV130, RV130W, and RV215W, representing a critical security flaw in the web-based management interface. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data, creating a pathway for malicious actors to manipulate the device's operating system through crafted HTTP requests. The vulnerability classifies under CWE-20, which specifically addresses improper input validation, a fundamental weakness that has been consistently identified as a primary attack vector in numerous security incidents. The affected devices operate on embedded operating systems that are particularly susceptible to such exploitation due to their limited security hardening and resource constraints typical of consumer-grade networking equipment.
The technical exploitation of CVE-2021-1212 requires an authenticated attacker with valid administrator credentials, which significantly reduces the attack surface compared to unauthenticated vulnerabilities but does not eliminate the risk entirely. Attackers can leverage this flaw by crafting malicious HTTP requests that bypass normal input validation checks, potentially leading to privilege escalation to root user level. This privilege escalation capability aligns with ATT&CK technique T1068, which describes the exploitation of legitimate credentials for privilege escalation. The successful exploitation can result in two primary outcomes: arbitrary code execution with root privileges or forced device restart, both of which can be leveraged for more sophisticated attacks. The root-level execution capability represents a particularly dangerous scenario as it allows complete system compromise and potential lateral movement within the network.
From an operational impact perspective, the vulnerability creates significant risk for organizations relying on these routers for network security and connectivity. The potential for arbitrary code execution means that attackers could install backdoors, modify network configurations, or establish persistent access points within the network infrastructure. The denial of service component of the vulnerability could be weaponized for disruption attacks, particularly in environments where network availability is critical. The fact that Cisco has not released software updates for these devices represents a substantial gap in security support, leaving affected organizations vulnerable to exploitation. This situation particularly impacts small and medium businesses that may not have dedicated security teams to monitor for and respond to such threats, making these devices attractive targets for cybercriminals seeking to establish footholds within corporate networks.
The remediation landscape for CVE-2021-1212 is severely limited due to the lack of official software updates from Cisco, forcing organizations to consider alternative mitigation strategies. Network segmentation and access control measures become critical defensive controls, particularly limiting administrative access to these devices through network access control lists and secure remote access protocols. Organizations should implement network monitoring to detect unusual traffic patterns or unauthorized administrative access attempts that might indicate exploitation attempts. The vulnerability's requirement for valid administrator credentials means that strong credential management practices, including regular credential rotation, multi-factor authentication where possible, and least privilege access controls, become essential defensive measures. Additionally, organizations should consider the implementation of network intrusion detection systems that can identify and alert on suspicious HTTP request patterns targeting web interfaces, as this represents a common exploitation method for similar vulnerabilities in network infrastructure devices.