CVE-2026-24415: Devcode OpenSTAManager XSS Vulnerability

CVE-2026-24415 Overview

OpenSTAManager is an open source management software for technical assistance and invoicing. A Reflected Cross-Site Scripting (XSS) vulnerability has been identified in OpenSTAManager v2.9.8 and earlier versions. The vulnerability exists in invoice, order, and contract modification modals where the application fails to properly sanitize user-supplied input from the righe GET parameter before reflecting it in HTML output. This allows attackers to inject arbitrary HTML and JavaScript code that executes in the context of victim users' browsers.

Critical Impact

Attackers can execute arbitrary JavaScript in victim browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of authenticated users.

Affected Products

• Devcode OpenSTAManager v2.9.8 and earlier versions
• All deployments using vulnerable invoice/order/contract modification modals
• Web-based installations accessible over network

Discovery Timeline

• 2026-03-03 - CVE CVE-2026-24415 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-24415

Vulnerability Analysis

This Reflected XSS vulnerability (CWE-79) occurs because the $_GET['righe'] parameter is directly echoed into the HTML value attribute without any sanitization. The application does not use htmlspecialchars() or equivalent encoding functions to neutralize special characters before incorporating user input into the page output. This oversight allows attackers to break out of the attribute context and inject malicious payloads.

The vulnerability affects multiple modal components within the application's invoice, order, and contract management functionality. When a user clicks a crafted malicious link, the injected script executes with the same privileges as the victim user, potentially compromising their session or performing actions on their behalf.

Root Cause

The root cause is improper input validation and missing output encoding in the PHP application code. The righe GET parameter value is inserted directly into an HTML attribute context without first being sanitized through proper encoding functions like htmlspecialchars($value, ENT_QUOTES, 'UTF-8'). This violates the secure coding principle of never trusting user input and always encoding output based on the context where it will be rendered.

Attack Vector

The attack is delivered via network-based vectors requiring user interaction. An attacker crafts a malicious URL containing JavaScript payload within the righe parameter and distributes it through phishing emails, social engineering, or embedding it in malicious websites. When an authenticated OpenSTAManager user clicks the link, the malicious script executes in their browser session. The attacker can then steal session cookies, capture keystrokes, redirect users to phishing pages, or perform actions within the application using the victim's credentials.

The vulnerability can be exploited by injecting a payload that escapes the value attribute context. For example, by including characters such as "> followed by a <script> tag or an event handler like onmouseover, the attacker breaks out of the intended HTML structure and introduces executable code.

Detection Methods for CVE-2026-24415

Indicators of Compromise

• Unusual URL patterns in web server logs containing the righe parameter with encoded JavaScript or HTML tags
• Access logs showing requests to invoice/order/contract modification endpoints with suspicious query strings containing script tags, event handlers, or encoded payloads
• Browser console errors or unexpected JavaScript execution reported by users
• Reports of unexpected behavior when accessing modification modals

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block requests containing common XSS patterns in the righe parameter
• Deploy browser-based Content Security Policy (CSP) headers to prevent inline script execution
• Monitor application logs for requests containing encoded characters like %3Cscript%3E, %22, or %27 in query parameters
• Utilize intrusion detection systems configured with XSS signature rules for HTTP traffic inspection

Monitoring Recommendations

• Enable detailed access logging for all endpoints handling invoice, order, and contract modifications
• Configure alerting for anomalous request patterns or high volumes of requests with unusual query parameters
• Implement real-time monitoring of client-side errors and unexpected JavaScript execution events
• Review referrer headers in logs to identify potential malicious redirect sources

How to Mitigate CVE-2026-24415

Immediate Actions Required

• Upgrade OpenSTAManager to the latest patched version as soon as available from the vendor
• Apply input validation to reject requests containing potentially malicious characters in the righe parameter
• Implement output encoding using htmlspecialchars() with ENT_QUOTES flag and UTF-8 encoding for all user-controlled values reflected in HTML
• Deploy Content Security Policy (CSP) headers to mitigate the impact of any successful XSS attacks

Patch Information

Refer to the GitHub Security Advisory for official patch information and updated versions. Organizations should update to the latest release of OpenSTAManager that addresses this vulnerability.

Workarounds

• Implement a web application firewall (WAF) rule to filter requests containing HTML/JavaScript payloads in the righe parameter
• Restrict access to affected modals to trusted networks or VPN-connected users only
• Educate users about the risks of clicking untrusted links, especially those containing lengthy or encoded query parameters
• Consider disabling affected functionality temporarily until a patch can be applied

# Example Apache ModSecurity rule to block potential XSS in righe parameter
SecRule ARGS:righe "@rx (?i)(<script|javascript:|on\w+=)" \
    "id:100001,phase:2,deny,status:403,msg:'Potential XSS in righe parameter'"