CVE-2019-20073 in DL4323
Summary
by MITRE
On Netis DL4323 devices, XSS exists via the form2userconfig.cgi username parameter (User Account Configuration).
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Analysis
by VulDB Data Team • 03/18/2024
The vulnerability identified as CVE-2019-20073 represents a cross-site scripting flaw discovered in Netis DL4323 devices, specifically within the form2userconfig.cgi component that handles user account configuration parameters. This issue arises from inadequate input validation and output sanitization mechanisms within the device's web interface, creating a persistent security weakness that can be exploited by malicious actors to execute arbitrary script code within the context of authenticated user sessions. The vulnerability is particularly concerning as it affects the core user management functionality of the device, potentially allowing attackers to manipulate user accounts and escalate privileges within the network infrastructure.
The technical exploitation of this vulnerability occurs through manipulation of the username parameter within the form2userconfig.cgi endpoint, which serves as the primary attack vector for the XSS payload delivery. When a user submits a specially crafted username containing malicious script code, the device fails to properly sanitize this input before rendering it in the web interface, thereby allowing the injected JavaScript to execute in the browser of any user who views the affected page. This flaw operates under the CWE-79 category of Cross-Site Scripting, specifically classified as a reflected XSS vulnerability where the malicious input is immediately reflected back to the user without proper encoding or validation. The vulnerability exists due to insufficient sanitization of user-supplied data within the device's web application framework, creating a direct pathway for persistent script injection attacks.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a range of malicious activities including session hijacking, credential theft, and unauthorized access to network resources. An attacker who successfully exploits this vulnerability could potentially gain access to administrative accounts, modify user permissions, or redirect users to malicious websites designed to harvest credentials or deploy additional malware. The attack surface is particularly broad given that the vulnerability affects the user account configuration interface, which is likely accessed by network administrators and authorized users during routine management tasks. This creates opportunities for attackers to establish persistent access to the device and potentially use it as a foothold for further network infiltration, particularly in environments where the device serves as a gateway or router component. The vulnerability also aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: JavaScript, as it enables the execution of malicious JavaScript code within the victim's browser context.
Mitigation strategies for CVE-2019-20073 should focus on implementing robust input validation and output encoding mechanisms within the device's web interface components. Network administrators should immediately update the firmware of affected Netis DL4323 devices to versions that address this vulnerability, as the manufacturer likely released patches to sanitize user input and prevent script injection attacks. Additionally, implementing proper content security policies and input sanitization routines within the web application framework can help prevent similar vulnerabilities from occurring in the future. Security monitoring should include detection of suspicious user account configuration activities and unusual parameter values that might indicate attempted exploitation of this vulnerability. Network segmentation and access control measures can also provide additional defense-in-depth layers to limit the potential impact if exploitation occurs. The vulnerability highlights the importance of secure coding practices and proper input validation in web applications, particularly those managing user account configurations and network access controls, as these components represent high-value targets for attackers seeking persistent access to network infrastructure.