zip1.io MCP

All 6 findings

1. high
   Tool `create_short_url` name implies a side effect that is not declared· create_short_urlexcessive agency

   `create_short_url` looks like a side-effecting tool (its name contains a mutation verb), but its `side_effects` declaration is []. A policy synthesizer cannot produce safe rules for this tool because it cannot tell what it actually does.

   fix: Declare the tool's true side effects explicitly. If the tool is genuinely read-only, rename it to match (e.g. `email.preview` rather than `email.send`).

2. high
   Tool `create_short_url` accepts an unconstrained URL / endpoint parameter· create_short_urlssrf surface

   The parameter(s) `url` look like URL or endpoint inputs but carry no `pattern` or `enum` constraint. An agent tricked by an indirect-injection payload can invoke this tool with an internal-service URL (e.g. `http://169.254.169.254/`) to exfiltrate cloud metadata, probe internal APIs, or pivot to services the host can reach but the caller cannot.

   fix: Constrain the URL parameter with an allow-list `enum`, or a `pattern` that restricts scheme and domain. Validate server-side against an allow-list and reject private / loopback / link-local address ranges at the HTTP client level.

3. high
   Tool `validate_url` accepts an unconstrained URL / endpoint parameter· validate_urlssrf surface

   The parameter(s) `url` look like URL or endpoint inputs but carry no `pattern` or `enum` constraint. An agent tricked by an indirect-injection payload can invoke this tool with an internal-service URL (e.g. `http://169.254.169.254/`) to exfiltrate cloud metadata, probe internal APIs, or pivot to services the host can reach but the caller cannot.

   fix: Constrain the URL parameter with an allow-list `enum`, or a `pattern` that restricts scheme and domain. Validate server-side against an allow-list and reject private / loopback / link-local address ranges at the HTTP client level.

4. medium
   Tool `create_short_url` accepts unconstrained string input· create_short_urlunconstrained input

   The following string parameter(s) have no `maxLength` constraint: `alias`, `description`, `expiration_time`, `password`, `url`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.

   fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.

5. medium
   Tool `get_url_stats` accepts unconstrained string input· get_url_statsunconstrained input

   The following string parameter(s) have no `maxLength` constraint: `short_code`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.

   fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.

6. medium
   Tool `validate_url` accepts unconstrained string input· validate_urlunconstrained input

   The following string parameter(s) have no `maxLength` constraint: `url`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.

   fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.