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 TDS message decoder in the Vert.x MSSQL client (vertx-mssql-client) aggregates inbound TDS packets into a composite direct-memory buffer without any cumulative size limit. A malicious, compromised, or man-in-the-middle SQL Server can send a continuous stream of TDS packets without setting the END_OF_MESSAGE status flag, 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-mssql-client.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Vert.x | Eclipse | 4.5.0 (including) | 4.5.35 (excluding) |
| Vert.x | Eclipse | 5.0.0 (including) | 5.1.10 (excluding) |
| Vert.x | Eclipse | 5.2.0 (including) | 5.2.0 (including) |
Potential Mitigations
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html