fix(security): validate the AWS region on the device-code route (SSRF)

The kiro / amazon-q device-code action interpolated a caller-supplied `region`
into the AWS OIDC endpoint URLs that requestDeviceCode() fetches, with no
validation — an attacker-shaped region (userinfo/fragment) could re-point the
outbound host to an internal target or the cloud-metadata service. `region` is
now checked against the canonical AWS region shape (AWS_REGION_PATTERN, already
used by pollToken) and rejected with a 400 before any outbound fetch.

Reported by @daniel-mertz via GHSA-7x63-xvp5-w2jc.

src/app/api/oauth/[provider]/[action]/route.ts

@@ -24,6 +24,7 @@ import {
 } from "@/models";
 import { getConsistentMachineId } from "@/shared/utils/machineId";
 import { isValidGheUrl } from "@/shared/validation/providerSpecificData";
+import { AWS_REGION_PATTERN } from "@/lib/oauth/constants/oauth";
 import { syncToCloud } from "@/lib/cloudSync";
 import { startLocalServer } from "@/lib/oauth/utils/server";
 import { runWithProxyContextOrDirect } from "@omniroute/open-sse/utils/proxyFetch.ts";
@@ -221,6 +222,16 @@ export async function GET(
             (requestDeviceCode as any)(provider, null, providerOverrideConfig)
           );
         } else if ((provider === "kiro" || provider === "amazon-q") && startUrl) {
+          // GHSA-7x63: `region` is interpolated into the AWS OIDC endpoint URLs
+          // below, which requestDeviceCode() then fetches. Validate it against the
+          // canonical AWS region shape before it can steer the outbound host to an
+          // attacker-chosen target (userinfo/fragment tricks → SSRF / metadata).
+          if (!AWS_REGION_PATTERN.test(region)) {
+            return NextResponse.json(
+              { error: "region must be a valid AWS region (e.g. us-east-1)" },
+              { status: 400 }
+            );
+          }
           const providerOverrideConfig = {
             ...providerData.config,
             startUrl,

tests/unit/oauth-device-code-region-ssrf.test.ts

@@ -0,0 +1,54 @@
+/**
+ * GHSA-7x63-xvp5-w2jc — the kiro / amazon-q device-code action interpolates a
+ * caller-supplied `region` into the AWS OIDC endpoint URLs that requestDeviceCode()
+ * fetches. An attacker-shaped region (userinfo / fragment) re-points the outbound
+ * host (SSRF → cloud metadata). The route must reject a non-canonical region with
+ * a 400 before any outbound fetch.
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import type { NextRequest } from "next/server";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omni-oauth-region-ssrf-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const route = await import("../../src/app/api/oauth/[provider]/[action]/route.ts");
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+async function deviceCode(provider: string, region: string) {
+  const url =
+    `http://localhost/api/oauth/${provider}/device-code` +
+    `?startUrl=${encodeURIComponent("https://d-1234567890.awsapps.com/start")}` +
+    `&region=${encodeURIComponent(region)}`;
+  return route.GET(new Request(url) as unknown as NextRequest, {
+    params: Promise.resolve({ provider, action: "device-code" }),
+  });
+}
+
+test("kiro device-code rejects a non-canonical region before any outbound fetch (GHSA-7x63)", async () => {
+  for (const bad of [
+    "evil.com",
+    "169.254.169.254",
+    "us-east-1@169.254.169.254",
+    "us-east-1#.amazonaws.com@evil.com",
+    "us-east-1/../..",
+    "US-EAST-1", // uppercase is not the canonical shape
+  ]) {
+    const res = await deviceCode("kiro", bad);
+    assert.equal(res.status, 400, `region "${bad}" must be rejected with 400`);
+  }
+});
+
+test("amazon-q device-code also validates region", async () => {
+  const res = await deviceCode("amazon-q", "evil.com:1@169.254.169.254");
+  assert.equal(res.status, 400);
+});