CVE-2019-20070 in DL4323
Summary
by MITRE
On Netis DL4323 devices, XSS exists via the urlFQDN parameter to form2url.cgi (aka the Keyword field of the URL Blocking Configuration).
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Analysis
by VulDB Data Team • 03/18/2024
The vulnerability identified as CVE-2019-20070 represents a cross-site scripting flaw discovered in Netis DL4323 network devices, specifically within the web interface administration functionality. This issue manifests through the urlFQDN parameter in the form2url.cgi script, which processes the Keyword field used for URL blocking configuration. The affected device operates with a web-based management interface that allows network administrators to configure various security policies including URL filtering and blocking mechanisms. When users interact with the URL Blocking Configuration section, the system fails to properly sanitize user input before processing it, creating an avenue for malicious actors to inject arbitrary script code.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the web application layer of the Netis DL4323 device. The urlFQDN parameter receives user-supplied data without proper encoding or filtering mechanisms that would prevent script execution. When an attacker submits malicious input containing javascript code or other malicious payloads through the Keyword field, the system stores and subsequently renders this data without adequate protection measures. This allows the malicious code to execute within the context of a victim's browser session, potentially enabling unauthorized actions such as cookie theft, session hijacking, or redirection to malicious sites. The vulnerability specifically targets the web interface administration component, making it accessible through standard HTTP requests to the form2url.cgi endpoint.
The operational impact of this XSS vulnerability extends beyond simple data theft or session manipulation, as it provides attackers with a potential foothold for more sophisticated attacks against the network infrastructure. An attacker could leverage this vulnerability to gain unauthorized access to the device's administrative interface, potentially leading to complete device compromise. The attack vector requires minimal privileges since the vulnerability exists in the web interface that is typically accessible to network administrators, though the exact access level required may vary based on device configuration. The vulnerability affects the device's URL filtering capabilities, which could be exploited to bypass security policies or redirect users to malicious domains. This type of vulnerability is particularly concerning in enterprise environments where network security devices are critical components of the overall security infrastructure.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and output encoding mechanisms within the affected web application. Network administrators should immediately apply firmware updates provided by Netis to address this vulnerability, as the manufacturer would have implemented proper sanitization of user input before processing. The solution involves ensuring that all user-supplied data passed to the urlFQDN parameter is properly encoded before being stored or rendered back to the browser. Additionally, implementing a content security policy that restricts script execution within the web interface can provide an additional layer of protection. Organizations should also consider network segmentation and access controls to limit exposure of administrative interfaces to untrusted networks. This vulnerability aligns with CWE-79 which defines cross-site scripting flaws, and could be mapped to ATT&CK technique T1059.007 for scripting execution through web interfaces, highlighting the need for comprehensive web application security controls and regular vulnerability assessments.