ZDI-21-821: (Pwn2Own) Microsoft Exchange Server Autodiscover Server Side Request Forgery Authentication Bypass Vulnerability
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Exchange Server. Authentication is not required to exploit this vulnerability. The specific flaw exists within the Autodiscover service. The issue results from the lack of proper validation of URI prior to accessing resources. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM.
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Microsoft Exchange |
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Reference Links
Frequently Asked Questions
What is the severity of ZDI-21-821?
ZDI-21-821 has a critical severity rating due to its potential for remote code execution without authentication.
How do I fix ZDI-21-821?
To fix ZDI-21-821, apply the latest security updates from Microsoft for Exchange Server.
Who is affected by ZDI-21-821?
ZDI-21-821 affects unpatched installations of Microsoft Exchange Server that utilize the Autodiscover service.
What type of vulnerability is ZDI-21-821?
ZDI-21-821 is a remote code execution vulnerability that allows attackers to execute arbitrary code on the affected systems.
Is authentication required to exploit ZDI-21-821?
No, authentication is not required to exploit the vulnerability identified in ZDI-21-821.
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