CVE-2019-25294 in html5_snmp
Summary
by MITRE • 02/06/2026
html5_snmp 1.11 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts through the 'Remark' parameter in add_router_operation.php. Attackers can craft a POST request with a script payload in the Remark field to execute arbitrary JavaScript in victim browsers when the page is loaded.
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Analysis
by VulDB Data Team • 03/03/2026
The vulnerability identified as CVE-2019-25294 represents a critical persistent cross-site scripting flaw within the html5_snmp 1.11 web application. This issue resides in the add_router_operation.php script where user input from the 'Remark' parameter is not properly sanitized or validated before being processed and displayed. The vulnerability classifies under CWE-79 which specifically addresses cross-site scripting flaws, making it a prime target for attackers seeking to exploit web application security weaknesses. The flaw exists because the application fails to implement proper input validation and output encoding mechanisms, allowing malicious payloads to persist in the application's data storage and subsequently execute in the context of victim browsers.
The technical exploitation of this vulnerability requires attackers to craft a malicious POST request containing a script payload within the Remark field of the add_router_operation.php endpoint. When the application processes this request and stores the data without adequate sanitization, the malicious script becomes embedded within the application's database or storage system. Subsequently, when legitimate users access pages that display this stored remark data, the embedded JavaScript executes within their browser context, potentially leading to session hijacking, credential theft, or further exploitation of the victim's browser environment. This persistent nature means that the malicious script remains active until explicitly removed from the application's data store, creating a long-term threat vector for attackers.
The operational impact of CVE-2019-25294 extends beyond simple script execution as it provides attackers with a means to establish persistent access to systems managed through the html5_snmp application. Attackers can leverage this vulnerability to steal user sessions, redirect victims to malicious sites, or even escalate privileges within the application's access control boundaries. The vulnerability's presence in a network management tool like html5_snmp creates additional risk as it may provide attackers with access to critical infrastructure monitoring data and potentially enable further attacks against network devices. This type of vulnerability directly aligns with attack patterns described in the MITRE ATT&CK framework under the T1059.007 technique for Scripting, where adversaries use malicious scripts to maintain persistence and execute commands within target environments.
Mitigation strategies for CVE-2019-25294 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application's data handling pipeline. The most effective immediate solution involves sanitizing all user-supplied input, particularly the Remark parameter, by employing proper HTML entity encoding before storing or displaying any user-generated content. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against script execution, while regular security audits should be conducted to identify and remediate similar vulnerabilities in other application components. The application should also implement proper parameter validation to reject or sanitize any input containing potentially dangerous script tags or JavaScript constructs, ensuring that all data flows through the application maintain security integrity and prevent the execution of unauthorized code within user browser contexts.