SRC-2020-0025 : Microsoft Exchange Server ExportExchangeCertificate WriteCertiricate File Write Remote Code Execution Vulnerability

CVE ID:

CVE-2020-17083

CVSS Score:

9.1, (/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C)

Affected Vendors:

Microsoft

Affected Products:

Exchange Server

Vulnerability Details:

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exchange Server. Authentication with the “Exchange Server Certificates” role is required to exploit this vulnerability.

The specific flaw exists within the WriteCertiricate function during the processing of the Export-ExchangeCertificate cmdlet. The issue results from the lack of proper validation of user-supplied data when writing files. An attacker can leverage this vulnerability to execute code in the context of SYSTEM.

Vendor Response:

Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2020-17083

Disclosure Timeline:

• 2020-06-04 – Sent to Microsoft
• 2020-11-10 – Coordinated public release of advisory

Proof of Concept:

• /pocs/cve-2020-17083.ps1.txt

Credit:

This vulnerability was discovered by Steven Seeley (mr_me) of Qihoo 360 Vulcan Team