CVE-2022-35523 in WN572HP3
Summary
by MITRE • 08/11/2022
WAVLINK WN572HP3, WN533A8, WN530H4, WN535G3, WN531P3 firewall.cgi has no filtering on parameter del_mac and parameter flag, which leads to command injection in page /cli_black_list.shtml.
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Analysis
by VulDB Data Team • 08/11/2022
The vulnerability identified as CVE-2022-35523 affects several WAVLINK wireless router models including WN572HP3, WN533A8, WN530H4, WN535G3, and WN531P3. This issue resides within the firewall.cgi script that manages network security policies on these devices. The flaw manifests as a lack of input validation and sanitization for two specific parameters: del_mac and flag. These parameters are processed within the context of the /cli_black_list.shtml page, which handles blacklist management for network devices. The absence of proper parameter filtering creates a critical command injection vulnerability that allows remote attackers to execute arbitrary commands on the affected devices with the privileges of the web server process. This vulnerability represents a classic case of insufficient input validation that directly enables arbitrary code execution, making it particularly dangerous for network infrastructure devices.
The technical exploitation of this vulnerability occurs through the manipulation of the del_mac and flag parameters in the firewall.cgi script. When these parameters are passed to the web application without proper sanitization, they can contain malicious command sequences that get executed within the context of the device's command processing. The vulnerability stems from the device's failure to properly validate or escape user-supplied input before incorporating it into system commands or shell executions. This type of flaw aligns with CWE-77 and CWE-89, which categorize improper input validation and command injection vulnerabilities respectively. The attack surface is particularly concerning because it allows unauthenticated remote command execution, meaning an attacker can exploit this vulnerability from outside the network without requiring valid credentials. The device's web interface serves as the attack vector, making the exploitation relatively straightforward for threat actors who can simply craft malicious HTTP requests to the vulnerable endpoint.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete device compromise and potential network infiltration. An attacker who successfully exploits this vulnerability can execute arbitrary commands on the router, potentially gaining full control over the network device's functionality. This includes the ability to modify network configurations, access sensitive data stored on the device, redirect network traffic, or establish persistent backdoors. The compromised device can then serve as a pivot point for attacking other systems within the local network, making this vulnerability particularly dangerous in enterprise environments where routers often serve as critical network infrastructure components. The vulnerability affects multiple device models from the same manufacturer, suggesting a systemic issue in the software development lifecycle that may have affected other components of the firmware. From an ATT&CK framework perspective, this vulnerability maps to techniques such as T1059.001 (Command and Scripting Interpreter: PowerShell) and T1021.001 (Remote Services: Remote Desktop Protocol) when considering the potential for lateral movement and remote code execution capabilities.
Mitigation strategies for this vulnerability should focus on immediate remediation through firmware updates provided by the manufacturer. Network administrators should prioritize patching affected devices as soon as updates become available, as the vulnerability allows for remote exploitation without authentication. In the absence of immediate patches, network segmentation and access controls can help limit the potential impact by restricting direct access to these devices from untrusted networks. Implementing network monitoring solutions that can detect unusual command execution patterns or unauthorized configuration changes can provide additional detection capabilities. The vulnerability highlights the importance of input validation and proper sanitization in web applications, particularly those running on network infrastructure devices. Organizations should conduct comprehensive vulnerability assessments of their network equipment to identify similar issues that may exist in other devices or components. Regular security audits of firmware and software components, combined with proper input validation practices, will help prevent similar vulnerabilities from arising in future deployments. The affected models should be isolated from critical network segments until proper patches are applied, and network traffic to these devices should be monitored for signs of exploitation attempts.