CVE-2021-38533 in RAX40
Summary
by MITRE • 08/11/2021
NETGEAR RAX40 devices before 1.0.3.64 are affected by stored XSS.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/16/2021
The vulnerability identified as CVE-2021-38533 affects NETGEAR RAX40 wireless routers running firmware versions prior to 1.0.3.64, representing a critical stored cross-site scripting flaw that enables attackers to execute malicious code within the context of a victim's browser session. This vulnerability resides in the device's web-based management interface, which fails to properly sanitize user input before storing and subsequently rendering it back to authenticated users. The stored XSS vulnerability specifically manifests when an attacker can inject malicious scripts into fields that are later displayed to other users who access the affected web interface, creating a persistent threat vector that can compromise user sessions and potentially lead to full device compromise.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding mechanisms within the NETGEAR RAX40's web administration panel. When users interact with the device configuration interface, particularly in fields such as device names, network settings, or other configurable parameters, the system does not adequately filter or escape special characters that could be interpreted as HTML or JavaScript code. This failure allows an attacker with access to the device's management interface to inject malicious payloads that persist in the device's storage and execute whenever the vulnerable interface is accessed by any authenticated user. The vulnerability operates under CWE-79 which classifies cross-site scripting as a result of insufficient sanitization of user-supplied data.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including session hijacking, credential theft, and unauthorized configuration changes. An attacker who successfully exploits this vulnerability can manipulate the device's network settings, redirect traffic through malicious proxies, or even establish persistent backdoors within the network infrastructure. The stored nature of the vulnerability means that once exploited, the malicious code remains active even after the initial injection point is closed, creating a persistent threat that can affect multiple users who access the device's management interface. This vulnerability directly aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1566.001 for credential access through social engineering, as the attack vector often involves user interaction with compromised management interfaces.
Mitigation strategies for CVE-2021-38533 primarily focus on firmware updates from NETGEAR, which provide the necessary patches to address the input validation gaps and implement proper output encoding mechanisms. Network administrators should immediately upgrade all affected RAX40 devices to firmware version 1.0.3.64 or later, as this update resolves the stored XSS vulnerability through enhanced input sanitization and proper HTML escaping of user-supplied content. Additionally, implementing network segmentation and access controls can limit the potential impact of exploitation, while regular security audits of network device configurations should be conducted to identify and remediate similar vulnerabilities. The vulnerability demonstrates the critical importance of secure coding practices and proper input validation in network infrastructure devices, as these systems often serve as primary attack vectors for broader network compromises. Organizations should also consider implementing web application firewalls and monitoring for suspicious activity in device management interfaces to detect potential exploitation attempts.