CVE-2019-25383 in Express
Summary
by MITRE • 02/16/2026
Smoothwall Express 3.1-SP4-polar-x86_64-update9 contains multiple reflected cross-site scripting vulnerabilities in the apcupsd.cgi script that allow attackers to inject malicious scripts through multiple POST parameters. Attackers can submit crafted POST requests with script payloads in parameters like BATTLEVEL, RTMIN, BATTDELAY, TO, ANNOY, UPSIP, UPSNAME, UPSPORT, POLLTIME, UPSUSER, NISPORT, UPSAUTH, EMAIL, FROM, CC, SMSEMAIL, SMTPSERVER, PORT, USER, and EMAIL_PASSWORD to execute arbitrary JavaScript in victim browsers.
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Analysis
by VulDB Data Team • 02/18/2026
The vulnerability identified as CVE-2019-25383 affects Smoothwall Express 3.1-SP4-polar-x86_64-update9, a network security appliance that provides firewall and intrusion prevention capabilities. This device incorporates the apcupsd.cgi script which serves as a web interface for managing power protection services and monitoring ups status. The affected system operates with a web-based management interface that processes user input through POST requests without adequate sanitization or validation of input parameters. The vulnerability represents a classic reflected cross-site scripting flaw that enables attackers to inject malicious JavaScript code into the web application's response, which then executes in the context of victim browsers accessing the compromised interface.
The technical exploitation of this vulnerability occurs through the manipulation of multiple POST parameters within the apcupsd.cgi script. Attackers can craft malicious POST requests containing script payloads in parameters including BATTLEVEL, RTMIN, BATTDELAY, TO, ANNOY, UPSIP, UPSNAME, UPSPORT, POLLTIME, UPSUSER, NISPORT, UPSAUTH, EMAIL, FROM, CC, SMSEMAIL, SMTPSERVER, PORT, USER, and EMAIL_PASSWORD. These parameters control various aspects of the ups monitoring and notification configuration, making them prime targets for injection attacks. When the web application processes these parameters without proper input validation or output encoding, the malicious scripts become reflected back to users who view the affected pages, enabling the execution of arbitrary JavaScript code in their browsers.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with a foothold for more sophisticated attacks within the network environment. An attacker who successfully exploits this vulnerability can potentially access sensitive system information, perform actions as authenticated users, or redirect victims to malicious websites. The reflected nature of the vulnerability means that attacks can be delivered through various vectors including phishing emails, compromised web pages, or direct exploitation of the web interface. The attack surface is particularly concerning given that Smoothwall appliances are often deployed in network security contexts where they serve as critical infrastructure components. The vulnerability could enable attackers to gain unauthorized access to the system's administrative functions, potentially leading to complete compromise of the network security appliance and underlying network.
Mitigation strategies for CVE-2019-25383 should focus on immediate input validation and output encoding implementation within the affected web application. Organizations should implement proper parameter validation for all input received through POST requests, particularly for parameters related to email addresses, server names, and configuration values. The implementation of Content Security Policy headers can provide additional protection against script execution in browser contexts. Network segmentation and access control measures should be enforced to limit exposure of the affected appliance to untrusted networks. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and represents a clear violation of secure coding practices that should be addressed through comprehensive input sanitization and output encoding. According to ATT&CK framework, this vulnerability maps to T1059.007 for script injection and T1566 for spearphishing with a link, as attackers could use this vulnerability to deliver malicious payloads through web-based attack vectors. Regular security updates and patch management procedures should be implemented to prevent exploitation of known vulnerabilities in network security appliances.