CVE-2021-1193 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 CVE-2021-1193 vulnerabilities affect Cisco Small Business routers including RV110W, RV130, RV130W, and RV215W models, representing critical security flaws in their web-based management interfaces. These devices operate as network gateways and security appliances in small business environments, making them attractive targets for cyber adversaries seeking to compromise network infrastructure. The vulnerabilities stem from inadequate input validation mechanisms that fail to properly sanitize user-supplied data within the web interface components. This fundamental flaw creates exploitable pathways for authenticated remote attackers who can leverage crafted HTTP requests to manipulate the underlying operating system. The affected devices run on embedded Linux systems with web servers that handle administrative functions, creating a surface area where improper input handling can lead to severe consequences. The vulnerability classification aligns with CWE-20, which addresses "Improper Input Validation," a well-documented weakness that frequently leads to arbitrary code execution and system compromise scenarios.
The technical exploitation of these vulnerabilities requires an attacker to possess valid administrator credentials, establishing a baseline authentication requirement that limits the attack surface but does not eliminate the risk entirely. Once authenticated, the attacker can craft malicious HTTP requests that bypass input validation controls, potentially leading to privilege escalation to root user level execution. This privilege escalation capability enables the attacker to execute arbitrary code on the device's operating system, effectively gaining complete control over the router's functionality. The exploitation can result in two primary outcomes: arbitrary code execution with root privileges or forced device reboots that create denial of service conditions. The latter scenario can be particularly disruptive in small business environments where router uptime is critical for network operations and connectivity. The web-based management interface typically processes configuration changes, user authentication, and system monitoring requests, making it a prime target for attackers seeking persistent access to network infrastructure.
The operational impact of these vulnerabilities extends beyond simple privilege escalation to encompass broader network security implications. Small business environments often rely on these routers for basic network security functions including firewalling, NAT, and DHCP services, making their compromise particularly damaging. The ability to execute arbitrary code as root user allows attackers to modify router configurations, install backdoors, redirect network traffic, or establish persistent access points within the network. The denial of service component creates additional risks by potentially disrupting network connectivity for extended periods, affecting business operations and productivity. Network administrators may face challenges in detecting exploitation attempts since legitimate administrative activities can mask malicious behavior within the web interface logs. The lack of available software updates from Cisco for these specific models compounds the risk, leaving affected organizations with limited remediation options and forcing them to rely on network segmentation and access controls as temporary mitigations.
Organizations affected by these vulnerabilities should implement immediate defensive measures including network segmentation to isolate critical infrastructure, strict access control policies for router management interfaces, and enhanced monitoring of administrative activities. The ATT&CK framework categorizes such vulnerabilities under T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1068 for "Exploitation for Privilege Escalation" when considering the exploitation paths. Additionally, these vulnerabilities align with NIST's cybersecurity framework's Protect function, particularly in areas related to system security and access control. Organizations should consider implementing network monitoring solutions to detect anomalous HTTP requests to management interfaces and establish incident response procedures for potential exploitation attempts. The absence of vendor patches for these specific models necessitates alternative security measures including physical security controls for router access, regular credential rotation, and network access controls that limit administrative access to trusted network segments. Security professionals should also consider these vulnerabilities when conducting risk assessments for small business network environments, as they represent a common attack vector that can lead to significant security breaches and operational disruptions.