CVE-2022-20876 in Small Business RV110W
Summary
by MITRE • 07/21/2022
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 on an affected device or cause the device to restart unexpectedly, resulting in a denial of service (DoS) condition. These vulnerabilities are due to insufficient validation of user fields within incoming HTTP packets. An attacker could exploit these vulnerabilities by sending a crafted request to the web-based management interface. A successful exploit could allow the attacker to execute arbitrary commands on an affected device with root-level privileges or to cause the device to restart unexpectedly, resulting in a 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 • 08/15/2022
The CVE-2022-20876 vulnerability represents a critical security flaw in Cisco Small Business routers including RV110W, RV130, RV130W, and RV215W models. This vulnerability exists within the web-based management interface of these network devices, creating a significant attack surface that could be exploited by authenticated remote adversaries. The flaw stems from inadequate input validation mechanisms that fail to properly sanitize user-provided data within HTTP packet headers and parameters. This type of vulnerability aligns with CWE-20, which specifically addresses "Improper Input Validation" in software systems. The affected devices are particularly concerning because they are commonly deployed in small business environments where network security may not be as rigorously maintained as in enterprise settings.
The technical exploitation of this vulnerability requires an attacker to possess valid administrator credentials for the affected router, which significantly reduces the attack surface compared to vulnerabilities requiring no authentication. However, the impact remains severe as successful exploitation grants attackers root-level privileges on the device. This privilege escalation allows for arbitrary code execution, enabling attackers to gain complete control over the router's operations and potentially use it as a pivot point for attacking other devices within the local network. The vulnerability can also be leveraged to cause unexpected device restarts, creating a denial of service condition that disrupts network connectivity for legitimate users. This dual capability of remote code execution and denial of service makes the vulnerability particularly dangerous in business environments where continuous network availability is critical.
The operational impact of CVE-2022-20876 extends beyond simple network disruption to encompass potential data breaches and network compromise. An attacker with root access could modify routing tables, redirect traffic through malicious servers, or establish backdoor access points for future exploitation. The vulnerability's presence in web-based management interfaces makes it especially concerning because these interfaces are often accessible from external networks for remote administration purposes, increasing the attack surface. According to ATT&CK framework, this vulnerability maps to techniques such as T1059.007 for command and scripting interpreter and T1499.004 for network disruption, demonstrating the multi-faceted nature of the threat. Organizations using these routers face significant risk of unauthorized network access and potential data exfiltration.
Cisco has not released software updates addressing these vulnerabilities, leaving affected organizations without official remediation paths. This lack of vendor support creates a particularly challenging scenario for network administrators who must balance immediate security needs with operational continuity. The vulnerability's exploitation requires minimal technical skill beyond having valid administrative credentials, making it accessible to a wide range of threat actors. Organizations should implement network segmentation to isolate affected devices, disable unnecessary web management interfaces, and enforce strict access controls for administrative accounts. Additionally, monitoring network traffic for suspicious HTTP requests and implementing intrusion detection systems can help identify potential exploitation attempts. The absence of official patches means that affected organizations must rely on workarounds such as disabling the web interface entirely or implementing additional authentication layers to mitigate the risk until a proper solution becomes available.