XSS Injection Vulnerability Report

[YLChen-007]

XSS Injection Vulnerability Report

Vulnerability Summary

Multiple Cross-Site Scripting (XSS) vulnerabilities exist in the application due to improper handling of user-supplied data. User input fields such as username and description are directly rendered into HTML without proper sanitization or encoding, allowing attackers to inject and execute malicious scripts.

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Affected Components

1. Member List Page (member-list.jsp)

Issue: The DataTables rendering function directly concatenates user input (e.g., username) into HTML strings without escaping, allowing script injection.

Vulnerable Code:

// Lines 103-137 in xmall-manager-web/src/main/webapp/WEB-INF/jsp/member-list.jsp
{ 
    "data": "username",
    render: function(data, type, row, meta){
        return "<u ...>" + data + "</a>";
    }
},
...
return "<a ... onclick=\"member_edit(...," + row.id + ",'','510')\" ...>";

Recommendation:

• Use .text() or textContent to insert user data as plain text
• Alternatively, use DataTables' built-in sanitization: render: $.fn.dataTable.render.text()
• Avoid direct string concatenation of user input in HTML contexts

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2. Member Detail Modal (member-show.jsp)

Issue: The detail page retrieves data from parent.username and other variables, then injects them into the DOM using .html(). Since the list data is already vulnerable to injection, using .html() executes any embedded malicious scripts.

Vulnerable Code:

// Lines 77-85 in xmall-manager-web/src/main/webapp/WEB-INF/jsp/member-show.jsp
$("#username").html(parent.username);
$("#description").html(parent.description);

Recommendation:

• Replace all .html() calls with .text() for text content
• Use .attr() for attributes like URLs
• Enforce text-only output to prevent script execution

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Recommendation:

• Apply HTML encoding or use text-only APIs consistently across both table rendering and modal population
• Implement the same fixes as recommended for the member pages

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Proof of Concept (POC) to member management

Step 1: Register User with Malicious Username

Register a new user with the username: <script>alert(1)</script>

Step 2: Trigger XSS on Admin Panel

Navigate to the user management page in the admin system. The injected script executes automatically, displaying an alert box.

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Impact

• Severity: High
• Attack Vector: Stored XSS
• Potential Impact:
  • Session hijacking and cookie theft
  • Admin account compromise
  • Unauthorized actions performed on behalf of authenticated users
  • Data exfiltration
  • Defacement of admin interface

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Remediation Summary

1. Input Validation: Implement strict input validation on the server-side for all user-supplied fields
2. Output Encoding: Apply context-appropriate output encoding (HTML entity encoding) for all user data displayed in HTML contexts
3. Use Safe APIs: Replace .html() with .text() for text content throughout the application
4. Content Security Policy: Implement a strict CSP to mitigate XSS impact
5. Security Testing: Conduct comprehensive security testing across all user input fields

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References

• OWASP XSS Prevention Cheat Sheet
• DataTables Security