fix(litellm): guard loopback hostname auto-allow with isIP to prevent DNS SSRF bypass (#110693)

* fix(litellm): guard loopback hostname auto-allow with isIP to prevent DNS bypass

The isAutoAllowedLitellmHostname helper auto-enables private-network access
for loopback-style hosts. Before this fix, lowered.startsWith("127.")
matched DNS hostnames like 127.evil.com, letting remote endpoints bypass
the explicit allowPrivateNetwork opt-in — a SSRF risk.

Add isIP(host)===4 guard so only literal IPv4 loopback addresses qualify.
Same canonical pattern as extensions/slack/src/monitor/relay-source.ts:271
and the codex loopback fix.

Co-Authored-By: Claude <noreply@anthropic.com>

* test(litellm): cover loopback endpoint policy

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

extensions/litellm/image-generation-provider.test.ts

@@ -254,7 +254,9 @@ describe("litellm image generation provider", () => {
     const cases = [
       "http://localhost:4000",
       "http://127.0.0.1:4000",
+      "http://127.255.255.254:4000",
       "http://[::1]:4000",
+      "http://[0:0:0:0:0:0:0:1]:4000",
       "http://host.docker.internal:4000",
       "https://localhost:4000",
     ] as const;
@@ -283,6 +285,7 @@ describe("litellm image generation provider", () => {
       "https://192.168.5.10:4000",
       "http://printer.local:4000",
       "http://proxy.internal:4000",
+      "http://127.evil.com:4000",
       "https://metadata.google.internal",
     ] as const;
     for (const baseUrl of cases) {
@@ -303,33 +306,36 @@ describe("litellm image generation provider", () => {
     }
   });
 
-  it("honors explicit private-network opt-in for a LAN LiteLLM proxy", async () => {
-    mockGeneratedPngResponse();
+  it.each(["http://192.168.5.10:4000", "http://127.evil.com:4000"])(
+    "honors explicit private-network opt-in for %s",
+    async (baseUrl) => {
+      mockGeneratedPngResponse();
 
-    const provider = buildLitellmImageGenerationProvider();
-    await provider.generateImage({
-      provider: "litellm",
-      model: "gpt-image-2",
-      prompt: "x",
-      cfg: {
-        models: {
-          providers: {
-            litellm: {
-              baseUrl: "http://192.168.5.10:4000",
-              request: { allowPrivateNetwork: true },
-              models: [],
+      const provider = buildLitellmImageGenerationProvider();
+      await provider.generateImage({
+        provider: "litellm",
+        model: "gpt-image-2",
+        prompt: "x",
+        cfg: {
+          models: {
+            providers: {
+              litellm: {
+                baseUrl,
+                request: { allowPrivateNetwork: true },
+                models: [],
+              },
             },
           },
         },
-      },
-    });
+      });
 
-    expectFields(mockObjectArg(resolveProviderHttpRequestConfigMock), {
-      allowPrivateNetwork: undefined,
-      request: { allowPrivateNetwork: true },
-    });
-    expect(mockObjectArg(postJsonRequestMock).allowPrivateNetwork).toBe(true);
-  });
+      expectFields(mockObjectArg(resolveProviderHttpRequestConfigMock), {
+        allowPrivateNetwork: undefined,
+        request: { allowPrivateNetwork: true },
+      });
+      expect(mockObjectArg(postJsonRequestMock).allowPrivateNetwork).toBe(true);
+    },
+  );
 
   it("does not allow private network for public hosts that embed private strings in the URL", async () => {
     // Must not be fooled by an attacker-controlled URL that mentions

extensions/litellm/image-generation-provider.ts

@@ -1,3 +1,4 @@
+import { isIP } from "node:net";
 // Litellm provider module implements model/runtime integration.
 import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";
 import {
@@ -62,7 +63,8 @@ function isAutoAllowedLitellmHostname(hostname: string): boolean {
   ) {
     return true;
   }
-  if (lowered === "127.0.0.1" || lowered.startsWith("127.")) {
+  // Only IPv4 literals may use the 127/8 loopback exemption.
+  if (isIP(lowered) === 4 && lowered.startsWith("127.")) {
     return true;
   }
   if (lowered === "::1" || lowered === "0:0:0:0:0:0:0:1") {