CVE-2019-9593 in Connect ONSITE
Summary
by MITRE
A reflected Cross-site scripting (XSS) vulnerability in ShoreTel Connect ONSITE 18.82.2000.0 allows remote attackers to inject arbitrary web script or HTML via the page parameter.
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Analysis
by VulDB Data Team • 09/14/2025
The vulnerability identified as CVE-2019-9593 represents a critical reflected cross-site scripting flaw within ShoreTel Connect ONSITE version 18.82.2000.0, a unified communications platform widely deployed in enterprise environments for voice and video conferencing services. This vulnerability resides in the web application interface of the system, specifically within the handling of user-supplied input through the page parameter. The flaw enables malicious actors to execute arbitrary web scripts or HTML code within the context of a victim's browser session, potentially compromising the security of authenticated users who interact with the vulnerable system.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding mechanisms within the ShoreTel application's web server component. When the application processes the page parameter without proper sanitization, it fails to escape or encode special characters that could be interpreted as HTML or JavaScript code. Attackers can craft malicious URLs containing script payloads that, when executed by a victim's browser, will be reflected back to the user interface without proper context-aware encoding. This creates a persistent vector for XSS exploitation where the malicious code executes in the victim's browser context with the privileges of the authenticated user, potentially enabling session hijacking, credential theft, or data exfiltration.
The operational impact of this vulnerability extends beyond simple script execution, as it can facilitate more sophisticated attacks within the enterprise network environment. An attacker who successfully exploits this vulnerability could potentially access sensitive communication data, intercept user sessions, or redirect victims to malicious sites for further exploitation. The vulnerability particularly affects organizations that rely on ShoreTel Connect ONSITE for their unified communications infrastructure, as the reflected nature of the XSS means that the attack requires user interaction through phishing emails or malicious links, making it particularly dangerous in social engineering campaigns. This vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and represents a direct violation of secure coding practices that require input validation and output encoding to prevent malicious code injection.
Organizations utilizing ShoreTel Connect ONSITE 18.82.2000.0 should implement immediate mitigations including applying the vendor-provided security patches, implementing web application firewalls to detect and block malicious payloads, and conducting thorough security assessments of the web application interface. Network segmentation and user access controls can help limit the potential impact if exploitation occurs. The vulnerability also highlights the importance of regular security updates and vulnerability management programs, as this flaw existed in a specific version of the software that had known remediation paths available through vendor patches. Security teams should monitor for exploitation attempts through log analysis and implement proper input validation mechanisms across all web applications to prevent similar vulnerabilities from being introduced in future deployments. This vulnerability demonstrates the critical need for continuous security monitoring and the implementation of defense-in-depth strategies that protect against both known and emerging threats in unified communications environments.