An information disclosure vulnerability exists when Microsoft Dynamics Business Central/NAV on-premise does not properly hide the value of a masked field when showing the records as a chart page.The attacker who successfully exploited the vulnerability could see the information that are in a masked field.The security update addresses the vulnerability by updating the rendering engine the Windows client to properly detect masked fields and render the content as masked., aka 'Microsoft Dynamics Business Central/NAV Information Disclosure'.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1018