SRC-2020-0023 : Microsoft SharePoint Server SoapDataSource GetResponseString Server-Side Request Forgery Information Disclosure Vulnerability

CVE ID: CVE-2020-16979

CVSS Score: 5.3, (/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C)

Affected Vendors: Microsoft

Affected Products: Microsoft SharePoint Server

Vulnerability Details:

This vulnerability allows remote attackers to disclose information on affected installations of SharePoint Server. Authentication is required to exploit this vulnerability.

The specific flaw exists within the SoapDataSource class. The issue results from the lack of proper validation of user-supplied SelectUrl property when performing data source access. An attacker can leverage this vulnerability to execute arbitrary web requests to protected resources.

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-2020-16979

Disclosure Timeline:

  • 2020-07-08 – 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