SRC-2021-0001 : Microsoft SharePoint Server ContentEditorWebPart GetHttpWebResponse Server-Side Request Forgery Information Disclosure Vulnerability

CVE ID: CVE-2021-1718

CVSS Score: 6.5, (/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C)

Affected Vendors: Microsoft

Affected Products: Microsoft SharePoint Server

Vulnerability Details:

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

The specific flaw exists within the ContentEditorWebPart class. The issue results from the lack of proper validation of the user-supplied ContentLink property. An attacker can leverage this vulnerability to execute arbitrary web requests to protected resources and disclose server responses.

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-2021-1718

Disclosure Timeline:

  • 2020-07-13 – Sent to Microsoft

  • 2021-01-12 – Coordinated public release of advisory

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