SRC-2020-0029 : Microsoft SharePoint Server DataFormParameter ParameterBinding Elevation of Privilege Vulnerability

CVE ID: CVE-2020-17089

CVSS Score: 7.1, (/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C)

Affected Vendors: Microsoft

Affected Products: SharePoint Server

Vulnerability Details:

This vulnerability allows remote attackers escalate privileges on affected installations of Microsoft SharePoint Server when form based authentication is enabled. Authentication is required to exploit this vulnerability.

The specific flaw exists within the Evaluate function inside of the DataFormParameter class. The issue results from the lack of proper validation on user-supplied properties when performing databinding. An attacker can leverage this vulnerability to escalate privileges to an administrative account.

Vendor Response:

Microsoft has issued an update to correct this vulnerability. More details can be found at: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-17089

Disclosure Timeline:

• 2020-07-14 – Sent to Microsoft

• 2020-09-08 – Coordinated public release of advisory

Credit: This vulnerability was discovered by Steven Seeley (mr_me) of Qihoo 360 Vulcan Team and Yuhao Weng (@cjm00nw)