feat: patch potential security vulnerability if private IP

package.json

@@ -17,6 +17,7 @@
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.0.4",
     "jsdom": "^25.0.1",
+    "private-ip": "^3.0.2",
     "turndown": "^7.2.0",
     "zod": "^3.24.1"
   },

pnpm-lock.yaml

@@ -14,6 +14,9 @@ importers:
       jsdom:
         specifier: ^25.0.1
         version: 25.0.1
+      private-ip:
+        specifier: ^3.0.2
+        version: 3.0.2
       turndown:
         specifier: ^7.2.0
         version: 7.2.0
@@ -210,6 +213,9 @@ packages:
   '@bcoe/v8-coverage@0.2.3':
     resolution: {integrity: sha512-0hYQ8SB4Db5zvZB4axdMHGwEaQjkZzFjQiN9LVYvIFB2nSUHW9tYpxWriPrWDASIxiaXax83REcLxuSdnGPZtw==}
 
+  '@chainsafe/is-ip@2.1.0':
+    resolution: {integrity: sha512-KIjt+6IfysQ4GCv66xihEitBjvhU/bixbbbFxdJ1sqCp4uJ0wuZiYBPhksZoy4lfaF0k9cwNzY5upEW/VWdw3w==}
+
   '@cspotcode/source-map-support@0.8.1':
     resolution: {integrity: sha512-IchNf6dN4tHoMFIn/7OE8LWZ19Y6q/67Bmf6vnGREv8RSbBVb9LPJxEcnwrcwX6ixSvaiGoomAUvu4YSxXrVgw==}
     engines: {node: '>=12'}
@@ -769,6 +775,14 @@ packages:
   inherits@2.0.4:
     resolution: {integrity: sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==}
 
+  ip-regex@5.0.0:
+    resolution: {integrity: sha512-fOCG6lhoKKakwv+C6KdsOnGvgXnmgfmp0myi3bcNwj3qfwPAxRKWEuFhvEFF7ceYIz6+1jRZ+yguLFAmUNPEfw==}
+    engines: {node: ^12.20.0 || ^14.13.1 || >=16.0.0}
+
+  ipaddr.js@2.2.0:
+    resolution: {integrity: sha512-Ag3wB2o37wslZS19hZqorUnrnzSkpOVy+IiiDEiTqNubEYpYuHWIf6K4psgN2ZWKExS4xhVCrRVfb/wfW8fWJA==}
+    engines: {node: '>= 10'}
+
   is-arrayish@0.2.1:
     resolution: {integrity: sha512-zz06S8t0ozoDXMG+ube26zeCTNXcKIPJZJi8hBrF4idCLms4CG9QtK7qBl1boi5ODzFpjswb5JPmHCbMpjaYzg==}
 
@@ -1048,6 +1062,10 @@ packages:
   natural-compare@1.4.0:
     resolution: {integrity: sha512-OWND8ei3VtNC9h7V60qff3SVobHr996CTwgxubgyQYEpg290h9J0buyECNNJexkFm5sOajh5G116RYA1c8ZMSw==}
 
+  netmask@2.0.2:
+    resolution: {integrity: sha512-dBpDMdxv9Irdq66304OLfEmQ9tbNRFnFTuZiLo+bD+r332bBmMJ8GBLXklIXXgxd3+v9+KUnZaUR5PJMa75Gsg==}
+    engines: {node: '>= 0.4.0'}
+
   node-int64@0.4.0:
     resolution: {integrity: sha512-O5lz91xSOeoXP6DulyHfllpq+Eg00MWitZIbtPfoSEvqIHdl5gfcY6hYzDWnj0qD5tz52PI08u9qUvSVeUBeHw==}
 
@@ -1129,6 +1147,10 @@ packages:
     resolution: {integrity: sha512-Pdlw/oPxN+aXdmM9R00JVC9WVFoCLTKJvDVLgmJ+qAffBMxsV85l/Lu7sNx4zSzPyoL2euImuEwHhOXdEgNFZQ==}
     engines: {node: ^14.15.0 || ^16.10.0 || >=18.0.0}
 
+  private-ip@3.0.2:
+    resolution: {integrity: sha512-2pkOVPGYD/4QyAg95c6E/4bLYXPthT5Xw4ocXYzIIsMBhskOMn6IwkWXmg6ZiA6K58+O6VD/n02r1hDhk7vDPw==}
+    engines: {node: '>=14.16'}
+
   prompts@2.4.2:
     resolution: {integrity: sha512-NxNv/kLguCA7p3jE8oL2aEBsrJWgAakBpgmgK6lpPWV+WuOmY6r2/zbAVnP+T8bQlA0nzHXSJSJW0Hq7ylaD2Q==}
     engines: {node: '>= 6'}
@@ -1646,6 +1668,8 @@ snapshots:
 
   '@bcoe/v8-coverage@0.2.3': {}
 
+  '@chainsafe/is-ip@2.1.0': {}
+
   '@cspotcode/source-map-support@0.8.1':
     dependencies:
       '@jridgewell/trace-mapping': 0.3.9
@@ -2315,6 +2339,10 @@ snapshots:
 
   inherits@2.0.4: {}
 
+  ip-regex@5.0.0: {}
+
+  ipaddr.js@2.2.0: {}
+
   is-arrayish@0.2.1: {}
 
   is-core-module@2.16.0:
@@ -2784,6 +2812,8 @@ snapshots:
 
   natural-compare@1.4.0: {}
 
+  netmask@2.0.2: {}
+
   node-int64@0.4.0: {}
 
   node-releases@2.0.19: {}
@@ -2853,6 +2883,13 @@ snapshots:
       ansi-styles: 5.2.0
       react-is: 18.3.1
 
+  private-ip@3.0.2:
+    dependencies:
+      '@chainsafe/is-ip': 2.1.0
+      ip-regex: 5.0.0
+      ipaddr.js: 2.2.0
+      netmask: 2.0.2
+
   prompts@2.4.2:
     dependencies:
       kleur: 3.0.3

src/Fetcher.ts

@@ -1,5 +1,6 @@
 import { JSDOM } from "jsdom";
 import TurndownService from "turndown";
+import is_ip_private from "private-ip";
 import { RequestPayload } from "./types.js";
 
 export class Fetcher {
@@ -8,6 +9,11 @@ export class Fetcher {
     headers,
   }: RequestPayload): Promise<Response> {
     try {
+      if (is_ip_private(url)) {
+        throw new Error(
+          `Fetcher blocked an attempt to fetch a private IP ${url}. This is to prevent a security vulnerability where a local MCP could fetch privileged local IPs and exfiltrate data.`,
+        );
+      }
       const response = await fetch(url, {
         headers: {
           "User-Agent":