A spoofing vulnerability exists in Microsoft Power BI Report Server in the way it validates the content-type of uploaded attachments. An authenticated attacker could exploit the vulnerability by uploading a specially crafted payload and sending it to the user. The attacker who successfully exploited this vulnerability could then perform actions and run scripts in the security context of the user. This security update addresses the vulnerability by ensuring Power BI Report Server properly validates content-type of the attachments when uploading and opening.
What version of Power BI has this vulnerability? The version of Power BI that contains the vulnerability is the May 2019 Release, version 1.5.7074.36177 (Build 15.0.1102.371). The vulnerability was addressed in the September 2019 release, version 1.6.7236.4246 (Build 15.0.1102.646). The most recent version of Power BI is the January 2020 release build is 15.0.1102.777.
Lukasz Plonka