Keylime registrar is vulnerable to Denial-of-Service attack when updated to version 7.12.0

Impact

The Keylime registrar implemented more strict type checking on version 7.12.0. As a result, when updated to version 7.12.0, the registrar will not accept the format of the data previously stored in the database by versions >= 7.8.0, raising an exception.

This makes the Keylime registrar vulnerable to a Denial-of-Service attack in an update scenario, as an attacker could populate the registrar database by creating multiple valid agent registrations with different UUIDs while the version is still < 7.12.0. Then, when the Keylime registrar is updated to the 7.12.0 version, any query to the database matching any of the entries populated by the attacker will result in failure.

Patches

Users should upgrade to versions >= 7.12.1

Workarounds

• Remove the registrar database and re-register all agents

Credit

Reported by: Anderson Toshiyuki Sasaki/@ansasaki
Patched by: Anderson Toshiyuki Sasaki/@ansasaki