From 751d170c94421fd6e5fe0e8cdabf7f48fdaf2f91 Mon Sep 17 00:00:00 2001
From: Ravi Tharuma <RaviTharuma@users.noreply.github.com>
Date: Mon, 20 Jul 2026 23:55:43 +0200
Subject: [PATCH] security: restrict plaintext HTTP to loopback

---
 src/plugin.ts        | 11 +++++++++++
 test/plugin.test.mjs | 10 +++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/plugin.ts b/src/plugin.ts
index d294271..5121b86 100644
--- a/src/plugin.ts
+++ b/src/plugin.ts
@@ -246,6 +246,13 @@ async function readAuthFromStore(
   }
 }
 
+function isLoopbackHostname(hostname: string): boolean {
+  const normalized = hostname.replace(/^\[|\]$/g, '').toLowerCase();
+  if (normalized === 'localhost' || normalized === '::1') return true;
+  const octets = normalized.split('.').map(Number);
+  return octets.length === 4 && octets.every(Number.isInteger) && octets[0] === 127;
+}
+
 export function getBaseUrl(
   options?: Record<string, unknown>,
   authBaseUrl?: string,
@@ -266,6 +273,10 @@ export function getBaseUrl(
         warn(`Ignoring unsupported baseURL protocol: ${sanitizeForLog(parsed.protocol)}`);
         continue;
       }
+      if (parsed.protocol === 'http:' && !isLoopbackHostname(parsed.hostname)) {
+        warn(`Ignoring insecure remote HTTP baseURL: ${sanitizeForLog(trimmed)}`);
+        continue;
+      }
       return trimmed.replace(/\/+$/, '');
     } catch {
       warn(`Ignoring invalid baseURL: ${sanitizeForLog(trimmed)}`);
diff --git a/test/plugin.test.mjs b/test/plugin.test.mjs
index 039ca7b..482a2d5 100644
--- a/test/plugin.test.mjs
+++ b/test/plugin.test.mjs
@@ -320,4 +320,12 @@ test('authorize stores baseURL and optional apiKey as JSON', async () => {
   const parsed = JSON.parse(result.key);
   assert.equal(parsed.baseURL, 'http://127.0.0.1:8317/v1');
   assert.equal(parsed.apiKey, '');
-});
\ No newline at end of file
+});
+test('getBaseUrl rejects plaintext HTTP for remote hosts but allows loopback', async () => {
+  const { getBaseUrl } = await import('../dist/src/plugin.js');
+  assert.equal(getBaseUrl({ baseURL: 'http://localhost:8317/v1' }), 'http://localhost:8317/v1');
+  assert.equal(getBaseUrl({ baseURL: 'http://127.42.0.1:8317/v1' }), 'http://127.42.0.1:8317/v1');
+  assert.equal(getBaseUrl({ baseURL: 'http://[::1]:8317/v1' }), 'http://[::1]:8317/v1');
+  assert.equal(getBaseUrl({ baseURL: 'http://proxy.example/v1' }), 'http://localhost:8317/v1');
+  assert.equal(getBaseUrl({ baseURL: 'http://192.168.1.10:8317/v1' }), 'http://localhost:8317/v1');
+});