Amazon Linux AMI Security Advisory: ALAS-2019-1246
Advisory Release Date: 2019-07-17 23:54 Pacific
Advisory Updated Date: 2019-07-25 18:48 Pacific
dbus as used in DBusServer, allows cookie spoofing because of symlink mishandling in the reference implementation of DBUS_COOKIE_SHA1 in the libdbus library. (This only affects the DBUS_COOKIE_SHA1 authentication mechanism.) A malicious client with write access to its own home directory could manipulate a ~/.dbus-keyrings symlink to cause a DBusServer with a different uid to read and write in unintended locations. In the worst case, this could result in the DBusServer reusing a cookie that is known to the malicious client, and treating that cookie as evidence that a subsequent client connection came from an attacker-chosen uid, allowing authentication bypass. (CVE-2019-12749)
Run yum update dbus to update your system.