CVE-2022-35526 in WN572HP3
Summary
by MITRE • 08/11/2022
WAVLINK WN572HP3, WN533A8, WN530H4, WN535G3, WN531P3 login.cgi has no filtering on parameter key, which leads to command injection in page /login.shtml.
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Analysis
by VulDB Data Team • 09/04/2022
The vulnerability identified as CVE-2022-35526 affects multiple WAVLINK wireless router models including WN572HP3, WN533A8, WN530H4, WN535G3, and WN531P3. This issue resides within the web interface authentication component where the login.cgi script fails to properly sanitize input parameters. The absence of parameter filtering on the key parameter creates a critical security flaw that allows attackers to inject arbitrary commands through the login page. The vulnerability specifically impacts the /login.shtml page where the command injection occurs, making it a direct threat to the device's operational integrity and network security. This type of vulnerability represents a classic command injection flaw that can be exploited to execute arbitrary code on the affected devices, potentially leading to complete system compromise.
The technical implementation of this vulnerability stems from inadequate input validation within the web application layer of the router firmware. When users attempt to authenticate through the login interface, the system processes the key parameter without proper sanitization or filtering mechanisms. This lack of input validation creates an environment where malicious actors can inject shell commands directly into the parameter value, which are then executed by the underlying operating system. The vulnerability operates at the application level and directly interfaces with the command execution functionality of the device, making it particularly dangerous as it bypasses normal authentication mechanisms. According to CWE standards, this represents a CWE-77 command injection vulnerability where user-supplied data is improperly incorporated into shell commands without adequate sanitization or escaping.
The operational impact of this vulnerability extends beyond simple unauthorized access to potentially full system compromise of the affected wireless routers. An attacker who successfully exploits this vulnerability can execute arbitrary commands with the privileges of the web server process, which typically runs with elevated permissions on the device. This could enable attackers to modify router configurations, install malicious firmware, establish backdoors, or use the device as a pivot point for attacking other systems within the local network. The vulnerability is particularly concerning because it affects multiple device models from the same manufacturer, suggesting a systemic flaw in the firmware development process that may be present across various products in the WAVLINK portfolio. Network administrators face the challenge of securing multiple devices simultaneously without proper patching mechanisms, as these devices may not support automatic updates or may require manual intervention.
Mitigation strategies for this vulnerability should focus on immediate remediation through firmware updates provided by WAVLINK, as well as network-level protective measures. Organizations should implement network segmentation to limit the potential impact of exploitation and ensure that affected devices are isolated from critical network segments. Network monitoring solutions should be configured to detect unusual command execution patterns or unauthorized access attempts that might indicate exploitation. The implementation of web application firewalls and input validation rules can provide additional protection layers to prevent malicious parameter injection. According to ATT&CK framework, this vulnerability maps to techniques involving command and script injection, where adversaries attempt to execute code through web applications. Security teams should also consider disabling unnecessary web management interfaces when not in use and implement strong authentication mechanisms including multi-factor authentication to reduce the attack surface. Regular vulnerability assessments and firmware update schedules should be established to prevent similar issues from arising in the future, as this vulnerability demonstrates the importance of proper input validation in embedded web applications.