In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the MySQL message decoder aggregates inbound multi-packet payloads into a composite direct-memory buffer without any cumulative size limit. A malicious, compromised, or man-in-the-middle MySQL server can send a continuous stream of packets with the maximum payload length (0xFFFFFF), preventing the end-of-message condition from being reached, causing unbounded direct-memory allocation on the client and leading to an out-of-memory crash. This occurs before authentication completes.

The impacted component is io.vertx:vertx-mysql-client.

In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x MySQL client (vertx-mysql-client) pre-allocates an array for column definitions based on a server-declared column count with no upper-bound validation. A malicious or compromised MySQL server, or an attacker with man-in-the-middle positioning, can send a crafted result set packet with an extremely large column count, causing the client to attempt a massive heap allocation. The resulting OutOfMemoryError crashes the Netty event loop thread, causing a complete denial of service for all connections and verticles in the Vert.x application.

The impacted component is io.vertx:vertx-mysql-client.

In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x Redis client RESP parser pre-allocates arrays to a length declared by the server without enforcing an upper bound. A malicious or compromised Redis server, or an attacker in a man-in-the-middle position, can send a crafted RESP response declaring an extremely large array, push, or attribute length, causing the client to attempt a massive heap allocation. The resulting OutOfMemoryError crashes the Vert.x event loop thread, denying service to all connections and verticles sharing that loop.

The impacted component is io.vertx:vertx-mysql-client.