SRC-2020-0026 : Microsoft Exchange Server NewExchangeCertificate WriteRequest File Write Remote Code Execution Vulnerability

CVE ID:

CVE-2020-17084

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:

Microsoft Exchange Server

Vulnerability Details:

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exchange Server. Authentication is required to exploit this vulnerability.

The specific flaw exists within the processing of the New-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-2020-17084

Disclosure Timeline:

  • 2020-06-05 – Sent to Microsoft
  • 2020-11-10 – Coordinated public release of advisory

Credit:

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