CVE-2020-3294 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 CVE-2020-3294 vulnerability affects Cisco Small Business routers including RV320 and RV325 series devices along with RV016 RV042 and RV082 models. This represents a critical security flaw in the web-based management interface that could be exploited by authenticated attackers with administrative privileges. The vulnerability stems from inadequate input validation mechanisms within the device's scripting components, creating a pathway for malicious input to be processed without proper boundary checks.
The technical exploitation of this vulnerability occurs through stack overflow conditions triggered by sending specially crafted requests containing excessively large input values to the affected web interface. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow which is classified as a fundamental weakness in software design that allows attackers to overwrite adjacent memory locations. The insufficient boundary restrictions on user-supplied input create a condition where attacker-controlled data can overflow the allocated stack space, potentially corrupting program execution flow and enabling arbitrary code execution.
From an operational perspective, successful exploitation of CVE-2020-3294 can result in complete system compromise with root privileges on the underlying operating system. The attack vector requires only administrative login credentials, making it particularly dangerous as it leverages legitimate administrative access to escalate privileges and execute malicious code. This vulnerability could be exploited to gain persistent access to network infrastructure, potentially enabling attackers to establish backdoors, exfiltrate sensitive data, or use the compromised device as a pivot point for further network attacks. The impact extends beyond individual device compromise as these small business routers often serve as critical network gateways.
The attack surface for this vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter where attackers can execute commands through the web interface. Additionally, the exploitation process follows T1068 Exploitation for Privilege Escalation patterns as attackers leverage existing administrative access to gain root-level control. Organizations using these router models face significant risk as the attack requires minimal privileges compared to other exploitation techniques. The vulnerability's impact is amplified by the widespread deployment of these devices in small business environments where network security awareness and patch management processes may be inadequate.
Mitigation strategies should include immediate patching of affected devices through official Cisco security advisories, network segmentation to limit access to administrative interfaces, and implementation of strong access controls with multi-factor authentication. Organizations should also consider monitoring for suspicious administrative activities and implementing network intrusion detection systems to identify potential exploitation attempts. Regular vulnerability assessments and security audits of network infrastructure are essential to identify similar weaknesses in other network devices that may be similarly vulnerable to input validation flaws. The vulnerability demonstrates the critical importance of proper input validation and boundary checking in web applications, particularly in network infrastructure devices where privilege escalation can lead to complete system compromise.