From prodefence.org
A security researcher revealed a new critical macOS Zero-day vulnerability in the keychain that is integrated into macOS allows an attacker to read all the Stored passwords in plain text.
Keychain Access is a macOS app that stores your passwords and account information and reduces the number of passwords you have to remember and manage whenever you access a website, email account, network server, or other password-protected items.
In this case, There is no admin or root permission needed in order to access the passwords from the keychain and the simple local user access is enough to exploit this Vulnerability.
This unpatched macOS Zero-day vulnerability affected the current Version of the macOS 10.14.3 and older versions.