CVE-2020-3296 in RV016
Summary
by MITRE
Multiple vulnerabilities in the web-based management interface of Cisco Small Business RV320 and RV325 Series Routers and Cisco Small Business RV016, RV042, and RV082 Routers could allow an authenticated, remote attacker with administrative privileges to execute arbitrary code on an affected device. The vulnerabilities are due to insufficient boundary restrictions on user-supplied input to scripts in the web-based management interface. An attacker with administrative privileges that are sufficient to log in to the web-based management interface could exploit each vulnerability by sending crafted requests that contain overly large values to an affected device, causing a stack overflow. A successful exploit could allow the attacker to cause the device to crash or allow the attacker to execute arbitrary code with root privileges on the underlying operating system.
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Analysis
by VulDB Data Team • 10/25/2020
The vulnerability identified as CVE-2020-3296 affects Cisco Small Business routers including the RV320 and RV325 series and the RV016, RV042, and RV082 models. This represents a critical security flaw in the web-based management interfaces of these network devices, which are commonly deployed in small business environments. The vulnerability stems from inadequate input validation mechanisms that fail to properly restrict user-supplied data passed to backend scripts, creating a dangerous pathway for exploitation. These routers serve as fundamental network infrastructure components, managing routing, firewalling, and network access control for small business networks, making their compromise particularly concerning from a cybersecurity perspective.
The technical implementation of this vulnerability involves insufficient boundary checks on user input within the web management interface scripts. When an authenticated attacker with administrative privileges submits crafted requests containing oversized data values, the system fails to properly validate these inputs before processing them through stack-based operations. This leads to stack overflow conditions that can be leveraged to execute arbitrary code with root privileges on the underlying operating system. The vulnerability specifically targets the input handling mechanisms of the web interface, where user-supplied data flows directly into script execution contexts without adequate sanitization or size limitation checks. The flaw is classified under CWE-121 as a stack-based buffer overflow, which is a well-known class of vulnerability that has been extensively documented in cybersecurity literature and represents one of the most dangerous types of memory corruption vulnerabilities.
The operational impact of this vulnerability is severe and potentially catastrophic for affected organizations. Successful exploitation allows attackers to gain complete control over the compromised router, enabling them to modify network routing tables, disable security features, redirect traffic through malicious endpoints, or establish persistent backdoors for future access. The ability to execute code with root privileges means that attackers can fundamentally alter the device's operation, potentially creating a foothold for broader network infiltration. Additionally, the device may become unstable or crash entirely, leading to denial of service conditions that can disrupt business operations. This vulnerability affects not just individual devices but entire network infrastructures since routers serve as critical communication hubs, and compromise of one device can facilitate lateral movement throughout the network.
Mitigation strategies for CVE-2020-3296 should prioritize immediate remediation through official Cisco security patches and firmware updates. Organizations must ensure that all affected router models receive the latest security updates from Cisco, which typically address the input validation issues by implementing proper boundary checks and size limitations on user-supplied data. Network segmentation and access control measures should be enhanced to limit administrative access to these devices, ensuring that only authorized personnel with legitimate business needs can access the web management interfaces. Implementing network monitoring solutions that can detect anomalous traffic patterns or unusual administrative activities may help identify potential exploitation attempts. Additionally, organizations should consider disabling unnecessary administrative access points and implementing multi-factor authentication where possible. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, making it a significant concern for organizations following the MITRE ATT&CK framework for threat modeling and defense planning.