Threat Model Analysis for vitessio/vitess

Threat: vtgate Query Manipulation

1. Threat: vtgate Query Manipulation
- Description: An attacker intercepts and modifies SQL queries sent through vtgate before they reach the vttablets. This could involve altering WHERE clauses, injecting malicious SQL code (if the application layer fails to prevent it), or changing the intended target keyspace/shard. The attacker might exploit a vulnerability in a network component between the application and vtgate, or compromise a poorly secured vtgate instance.
- Impact:
  - Data corruption or unauthorized data modification.
  - Data exfiltration (reading data the attacker shouldn't have access to).
  - Denial of service by sending malformed or resource-intensive queries.
  - Bypassing application-level security controls.
- Affected Component: vtgate (specifically, the query parsing and routing logic).
- Risk Severity: Critical
- Mitigation Strategies:
  - Enforce TLS: Use TLS encryption for all communication between the application and vtgate. Ensure proper certificate validation.
  - Network Segmentation: Isolate vtgates in a secure network segment, limiting access only to authorized application servers.
  - vtgate Hardening: Regularly patch vtgate. Minimize its attack surface by disabling unnecessary features.
  - Rate Limiting: Implement rate limiting on vtgate to prevent abuse.

2. Threat: vttablet Direct Access
- Description: An attacker bypasses vtgate and directly connects to a vttablet instance. This could be due to network misconfiguration, firewall rule errors, or exploitation of a vulnerability in vttablet itself.
- Impact:
  - Direct access to the data stored on that specific shard.
  - Ability to execute arbitrary SQL commands on that shard's database.
  - Data exfiltration, modification, or deletion.
  - Disruption of replication for that shard.
- Affected Component: vttablet (and the underlying MySQL/MariaDB instance).
- Risk Severity: Critical
- Mitigation Strategies:
  - Strict Network Segmentation: vttablets should never be directly accessible from the application servers or the public internet. Only vtgates and other authorized Vitess components (e.g., other vttablets for replication) should be able to connect.
  - Firewall Rules: Implement strict firewall rules to enforce network segmentation.
  - vttablet Hardening: Regularly patch vttablet and the underlying database server.
  - Host-Based Intrusion Detection: Use HIDS/HIPS on vttablet hosts.
  - Encrypted Communication: Enforce TLS between vtgates and vttablets.

3. Threat: Topology Service Poisoning
- Description: An attacker compromises the topology service (etcd, ZooKeeper, Consul) or vtctld and modifies the cluster configuration. This could involve changing the mapping of shards to vttablets, redirecting traffic to malicious vttablets, or disabling parts of the cluster.
- Impact:
  - Complete cluster disruption.
  - Redirection of queries to attacker-controlled servers.
  - Data loss or corruption.
  - Denial of service.
- Affected Component: vtctld, Topology Service (etcd, ZooKeeper, Consul).
- Risk Severity: Critical
- Mitigation Strategies:
  - Highly Restricted Access: Limit access to vtctld and the topology service to a very small number of authorized administrators.
  - Strong Authentication: Use multi-factor authentication for access.
  - Network Segmentation: Isolate the topology service in a highly secure network segment.
  - Regular Patching: Keep vtctld and the topology service software up-to-date.
  - Auditing: Enable detailed auditing of all changes to the topology service.
  - Backup and Recovery: Regularly back up the topology service data.
  - Dedicated Infrastructure: Consider running the topology service on dedicated, hardened infrastructure.

4. Threat: Exploitation of Vulnerabilities in Vitess Code
- Description: An attacker discovers and exploits a vulnerability in the Vitess codebase itself (vtgate, vttablet, vtctld, etc.). This could be a buffer overflow, a logic error, or any other type of software flaw.
- Impact:
  - Varies widely depending on the vulnerability. Could range from denial of service to arbitrary code execution and complete system compromise.
- Affected Component: Potentially any Vitess component (vtgate, vttablet, vtctld, etc.).
- Risk Severity: High to Critical (depending on the vulnerability)
- Mitigation Strategies:
  - Regular Updates: Keep Vitess updated to the latest stable release to receive security patches.
  - Vulnerability Scanning: Use vulnerability scanners to identify known vulnerabilities in Vitess and its dependencies.
  - Security Audits: Consider conducting periodic security audits of the Vitess deployment.

5. Threat: Denial of Service via Resource Exhaustion on vtgate
- Description: An attacker floods vtgate with a large number of requests, exceeding its capacity to handle them. This could be a simple flood of connections or a more sophisticated attack targeting specific Vitess features.
- Impact:
  - Denial of service for legitimate users.
  - Application downtime.
- Affected Component: vtgate
- Risk Severity: High
- Mitigation Strategies:
  - Rate Limiting: Implement rate limiting on vtgate to limit the number of requests from a single source.
  - Connection Limits: Configure connection limits to prevent a single client from consuming all available connections.
  - Resource Allocation: Ensure that vtgate has sufficient resources (CPU, memory, network bandwidth) to handle expected traffic loads.
  - Load Balancing: Distribute traffic across multiple vtgate instances using a load balancer.