CVE-2026-30252: ZenShare Suite XSS Vulnerability

CVE-2026-30252 Overview

Multiple reflected cross-site scripting (XSS) vulnerabilities have been discovered in the login.php endpoint of Interzen Consulting S.r.l ZenShare Suite v17.0. These vulnerabilities allow attackers to execute arbitrary JavaScript code in the context of a victim's browser session by crafting malicious URLs that inject payloads into the codice_azienda and red_url parameters.

Reflected XSS attacks occur when user-supplied input is immediately returned by the web application without proper sanitization or encoding. In this case, the login page fails to adequately validate or encode these parameters before reflecting them back in the HTML response, creating an opportunity for attackers to inject malicious scripts.

Critical Impact

Attackers can steal user session tokens, credentials, and sensitive data by tricking authenticated users into clicking malicious links targeting the vulnerable ZenShare Suite login page.

Affected Products

• Interzen Consulting S.r.l ZenShare Suite v17.0
• ZenShare Suite login.php endpoint

Discovery Timeline

• 2026-04-02 - CVE-2026-30252 published to NVD
• 2026-04-02 - Last updated in NVD database

Technical Details for CVE-2026-30252

Vulnerability Analysis

The vulnerability resides in the authentication flow of ZenShare Suite, specifically within the login.php endpoint. Two parameters have been identified as vulnerable to reflected XSS attacks: codice_azienda (company code) and red_url (redirect URL).

When a user navigates to the login page with specially crafted parameter values, the application reflects these values directly into the HTML response without proper output encoding or input validation. This behavior allows an attacker to inject arbitrary JavaScript that executes within the security context of the ZenShare Suite application domain.

The exploitation of this vulnerability is particularly concerning in an enterprise environment where ZenShare Suite is used for document management and collaboration. Successful exploitation could lead to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim user.

Root Cause

The root cause of this vulnerability is improper input validation and insufficient output encoding in the login.php script. The codice_azienda and red_url parameters accept user-controlled input that is subsequently reflected in the HTML response without being sanitized or properly escaped.

This represents a failure to implement defense-in-depth principles, where user input should be validated on input and encoded on output. The application trusts user-supplied data and incorporates it directly into the page content, violating the principle of treating all external input as potentially malicious.

Attack Vector

The attack vector for CVE-2026-30252 is network-based, requiring user interaction. An attacker would craft a malicious URL containing JavaScript payload in either the codice_azienda or red_url parameter and distribute it to potential victims through phishing emails, social engineering, or by embedding it in compromised web pages.

When a victim clicks the malicious link while authenticated to ZenShare Suite (or navigating to authenticate), the injected JavaScript executes in their browser with full access to the application's DOM, cookies (if not HttpOnly), and session storage.

The vulnerability requires an attacker to deliver the malicious link to the victim through social engineering techniques. A typical attack scenario involves embedding the malicious URL in a phishing email that appears to originate from a trusted source, enticing users to click through to what appears to be the legitimate ZenShare login page.

For detailed technical information about this vulnerability, refer to the GitHub PoC Repository.

Detection Methods for CVE-2026-30252

Indicators of Compromise

• Unusual URL patterns in web server logs containing encoded JavaScript in the codice_azienda or red_url parameters of login.php
• Network traffic showing requests to login.php with suspicious parameter values containing <script> tags, event handlers, or JavaScript protocol handlers
• User reports of unexpected browser behavior or pop-ups when accessing the ZenShare Suite login page
• Authentication logs showing login attempts from unusual geographic locations following link-based attacks

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common XSS patterns in URL parameters targeting the login.php endpoint
• Implement Content Security Policy (CSP) headers with strict script-src directives to prevent inline script execution
• Monitor web server access logs for requests containing HTML/JavaScript encoding patterns in query strings
• Configure SIEM alerts for anomalous patterns in authentication-related web traffic

Monitoring Recommendations

• Enable detailed logging for the ZenShare Suite web application to capture full request URLs including query parameters
• Implement real-time log analysis to detect XSS attack patterns targeting the vulnerable parameters
• Monitor for unusual session behavior that may indicate successful credential theft following XSS exploitation
• Track user-agent anomalies and referrer patterns that may indicate phishing campaign activity

How to Mitigate CVE-2026-30252

Immediate Actions Required

• Implement input validation on the codice_azienda and red_url parameters to reject requests containing HTML special characters or JavaScript patterns
• Apply output encoding using context-appropriate encoding functions when reflecting parameter values in HTML responses
• Deploy a Web Application Firewall with XSS protection rules as an interim measure while awaiting vendor patches
• Educate users about the risks of clicking suspicious links, particularly those appearing to lead to the ZenShare Suite login page

Patch Information

As of the publication date, no official patch information has been provided by Interzen Consulting S.r.l for this vulnerability. Organizations should monitor vendor communications and the GitHub PoC Repository for updates regarding available patches or official remediation guidance.

Contact Interzen Consulting S.r.l directly to inquire about security updates for ZenShare Suite v17.0.

Workarounds

• Implement a reverse proxy or WAF rule to sanitize or block requests containing script tags or JavaScript event handlers in the codice_azienda and red_url parameters
• Restrict access to the ZenShare Suite login page to trusted IP ranges or VPN users until a patch is available
• Enable strict Content Security Policy headers to prevent execution of inline scripts, reducing the impact of successful XSS injection
• Consider implementing additional authentication factors that are not susceptible to session token theft

# Example WAF rule for ModSecurity to block XSS attempts on login.php
SecRule REQUEST_URI "@contains /login.php" \
    "id:100001,phase:1,deny,status:403,\
    chain,msg:'Potential XSS in ZenShare login parameters'"
    SecRule ARGS:codice_azienda|ARGS:red_url "@rx (?i)(<script|javascript:|on\w+=)" \
        "t:urlDecodeUni,t:htmlEntityDecode"