CVE-2023-20147 in Small Business RV016
Summary
by MITRE • 04/05/2023
Multiple vulnerabilities in the web-based management interface of Cisco Small Business RV016, RV042, RV042G, RV082, RV320, and RV325 Routers could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the interface. These vulnerabilities are due to insufficient input validation by the web-based management interface. An attacker could exploit these vulnerabilities by sending crafted HTTP requests to an affected device and then persuading a user to visit specific web pages that include malicious payloads. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. Cisco has not released software updates that address these vulnerabilities.
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Analysis
by VulDB Data Team • 08/25/2025
The vulnerability identified as CVE-2023-20147 represents a critical cross-site scripting flaw affecting multiple Cisco Small Business routers including the RV016, RV042, RV042G, RV082, RV320, and RV325 models. This security weakness resides within the web-based management interface of these network devices, creating a significant attack surface that can be exploited by unauthenticated remote adversaries. The vulnerability stems from inadequate input validation mechanisms implemented by Cisco's web interface, which fails to properly sanitize user-supplied data before processing or rendering it within the browser context. This fundamental flaw allows attackers to inject malicious scripts that can execute in the context of authenticated users who interact with the compromised interface.
The technical exploitation of this vulnerability follows a classic XSS attack pattern where an attacker crafts malicious HTTP requests designed to target specific parameters within the router's web management interface. These crafted requests typically involve injecting script payloads into input fields or URL parameters that are not adequately validated or escaped. The attack vector leverages the trust relationship between the web interface and the user's browser, where a victim user who accesses the compromised interface will unknowingly execute the malicious code embedded within the router's response. The vulnerability specifically affects the web-based management interface which is commonly used by administrators and users to configure and monitor network settings, making it a prime target for exploitation.
From an operational impact perspective, successful exploitation of these vulnerabilities can lead to severe consequences including unauthorized access to router configuration settings, data exfiltration, session hijacking, and potential lateral movement within the network. The attacker could execute arbitrary code within the browser context of the management interface, potentially allowing them to modify router settings, redirect traffic, or establish persistent access points. Additionally, the vulnerability enables attackers to access sensitive browser-based information that might include session cookies, authentication tokens, or other credentials that could be used to escalate privileges or gain deeper access to the network infrastructure. The lack of available software updates from Cisco for these specific vulnerabilities creates a prolonged window of exposure for affected organizations.
The vulnerability aligns with CWE-79 which describes Cross-Site Scripting flaws in web applications, and represents a clear violation of secure coding practices that should prevent untrusted data from being directly rendered in browser contexts without proper sanitization. From an ATT&CK framework perspective, this vulnerability maps to techniques such as T1059.007 (Command and Scripting Interpreter: JavaScript) and T1566 (Phishing) as attackers may need to lure victims into visiting compromised pages. Organizations should implement network segmentation to isolate these devices from critical systems, deploy web application firewalls to filter malicious requests, and consider disabling the web management interface when not actively required. The absence of official patches from Cisco underscores the importance of network monitoring and intrusion detection systems to identify potential exploitation attempts, while also highlighting the need for organizations to maintain awareness of vendor security advisories and consider alternative network management approaches for affected devices.