CVE-2020-3147 in Small Business Switches
Summary
by MITRE
A vulnerability in the web UI of Cisco Small Business Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of requests sent to the web interface. An attacker could exploit this vulnerability by sending a malicious request to the web interface of an affected device. A successful exploit could allow the attacker to cause an unexpected reload of the device, resulting in a DoS condition. This vulnerability affects firmware releases prior than 1.3.7.18
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Analysis
by VulDB Data Team • 03/27/2024
The vulnerability identified as CVE-2020-3147 resides within the web user interface of Cisco Small Business Switches, representing a critical security weakness that undermines the operational integrity of network infrastructure devices. This flaw specifically targets the authentication mechanisms and request validation processes implemented within the web management interface of affected switching hardware. The vulnerability stems from insufficient input validation procedures that fail to properly sanitize or verify the legitimacy of incoming HTTP requests directed toward the device's web UI. Cisco Small Business Switches are commonly deployed in enterprise environments where network reliability and uptime are paramount, making this vulnerability particularly concerning for organizations relying on these devices for critical network operations.
The technical exploitation of CVE-2020-3147 occurs through the manipulation of HTTP requests sent to the web interface of vulnerable devices, where the absence of proper validation allows malicious actors to craft specially formatted requests that trigger unintended behavior within the device's processing logic. When an attacker successfully crafts and delivers such a malicious request, the device's web interface fails to properly handle the malformed input, leading to an unexpected system reload or reboot cycle. This process effectively causes a denial of service condition that disrupts network operations and can result in complete network outages depending on the switch's role within the infrastructure. The vulnerability specifically impacts firmware versions prior to 1.3.7.18, indicating that Cisco has acknowledged and addressed this weakness in subsequent releases through proper input validation mechanisms and enhanced request handling procedures.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network stability and availability across enterprise environments. Organizations utilizing affected Cisco Small Business Switches face significant risk of unauthorized attackers exploiting this weakness to repeatedly cause device reboots, creating a persistent DoS condition that can severely impact business operations and network performance. The unauthenticated nature of this vulnerability means that attackers do not require valid credentials to exploit the weakness, making it particularly dangerous as it can be leveraged by any individual with network access to the device's web interface. Network administrators must consider the potential for cascading failures if multiple switches in a network are affected, as the coordinated exploitation of multiple devices could result in widespread network disruption.
Mitigation strategies for CVE-2020-3147 primarily focus on firmware updates and network access controls to prevent exploitation of the vulnerability. Organizations should immediately upgrade affected Cisco Small Business Switches to firmware version 1.3.7.18 or later, which includes the necessary patches to address the improper request validation issue. Additionally, network segmentation and access control measures should be implemented to restrict access to the web management interface, particularly by limiting access to trusted network segments and implementing strong authentication mechanisms. The vulnerability aligns with CWE-20, which describes improper input validation as a fundamental weakness that can lead to various security issues including DoS conditions. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service attacks, and represents a critical entry point for attackers seeking to disrupt network operations through system instability. Organizations should also implement network monitoring to detect unusual traffic patterns or repeated connection attempts that may indicate exploitation attempts against this vulnerability.