This vulnerability combines a missing authorization check with a path‑traversal flaw in the cloud‑storage source of Google Cloud's MCP Toolbox for Databases. An unauthenticated remote attacker can supply crafted invocation parameters that cause the tool to read any files on the host and to overwrite any local files, or to exfiltrate those files to arbitrary Google Cloud Storage buckets. The flaw therefore jeopardizes the confidentiality of host data and the integrity of the file system, allowing the attacker to modify or remove critical files without any authentication.

The affected product is Google Cloud MCP Toolbox for Databases (googleapis/mcp-toolbox). Versions 1.2.0 through 1.4.0 are vulnerable; remediation is achieved by upgrading to 1.5.0 or later.

The CVSS score of 9.3 places this issue in the critical range, indicating a high impact. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog. Although the exact attack vector is not explicitly provided, it is inferred that an attacker can trigger exploitation remotely via the tool’s API or command‑line interface using unauthenticated requests. The missing authentication combined with traversal routes offers a straightforward path to read, write, or delete arbitrary files on the host system.