CVE-2021-1187 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 vulnerability identified as CVE-2021-1187 affects Cisco Small Business routers including the RV110W, RV130, RV130W, and RV215W models, presenting a critical security risk through their web-based management interfaces. These devices operate within small office and home office environments where they serve as primary network gateways, making their security paramount to overall network integrity. The vulnerability stems from insufficient input validation mechanisms within the web interface, creating pathways for malicious actors to manipulate the system through carefully crafted HTTP requests. This flaw represents a classic example of improper input validation that falls under the CWE-20 category, specifically addressing weaknesses in input sanitization and validation processes.
The technical exploitation of this vulnerability 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 submit malicious HTTP requests that bypass normal input validation checks, potentially leading to arbitrary code execution with root privileges on the underlying operating system. This privilege escalation capability is particularly dangerous as it allows attackers to gain complete control over the device, enabling them to modify network configurations, install malicious software, or establish persistent access points. The vulnerability also permits denial of service conditions through device reloads, which can disrupt network connectivity for legitimate users and potentially create opportunities for further attacks.
The operational impact of CVE-2021-1187 extends beyond immediate device compromise, as these routers often serve as the first line of defense in network security architectures. When compromised, these devices can be used as launching points for attacks against internal network resources, potentially enabling lateral movement and data exfiltration. The lack of available software updates from Cisco for this vulnerability creates a persistent risk for affected organizations, as they cannot rely on vendor-provided patches to resolve the issue. This situation aligns with ATT&CK technique T1059.007, which describes the use of command and scripting interpreter for execution, as attackers could leverage the arbitrary code execution capability to deploy additional malicious tools or establish backdoors. Network administrators must consider implementing alternative security controls including network segmentation, intrusion detection systems, and regular security assessments to mitigate the risk posed by this vulnerability.
Organizations utilizing these affected router models should implement immediate defensive measures including strict access controls, monitoring of administrative access logs, and network-based detection of suspicious HTTP traffic patterns. The vulnerability's classification as a remote code execution flaw under the Common Vulnerability Scoring System (CVSS) indicates a high severity rating, emphasizing the urgency of mitigation efforts. Security teams should also consider conducting vulnerability assessments to identify potentially compromised systems and develop incident response procedures that account for the possibility of complete device takeover. The absence of vendor patches for this vulnerability underscores the importance of maintaining awareness of third-party security advisories and implementing compensating controls to protect against known threats.