JS: Handle Next.js files named 'page' or 'route'

javascript/ql/lib/semmle/javascript/frameworks/Next.qll

@@ -13,39 +13,40 @@ module NextJS {
    */
   PackageJson getANextPackage() { result.getDependencies().getADependency("next", _) }
 
-  bindingset[base, name]
-  pragma[inline_late]
-  private Folder getOptionalFolder(Folder base, string name) {
-    result = base.getFolder(name)
-    or
-    not exists(base.getFolder(name)) and
-    result = base
-  }
-
   private Folder packageRoot() { result = getANextPackage().getFile().getParentContainer() }
 
-  private Folder srcRoot() { result = getOptionalFolder(packageRoot(), "src") }
+  private Folder srcRoot() { result = [packageRoot(), packageRoot().getFolder("src")] }
 
   private Folder appRoot() { result = srcRoot().getFolder("app") }
 
   private Folder pagesRoot() { result = [srcRoot(), appRoot()].getFolder("pages") }
 
   private Folder apiRoot() { result = [pagesRoot(), appRoot()].getFolder("api") }
 
+  private Folder appFolder() {
+    result = appRoot()
+    or
+    result = appFolder().getAFolder()
+  }
+
+  private Folder pagesFolder() {
+    result = pagesRoot()
+    or
+    result = pagesFolder().getAFolder()
+  }
+
   /**
    * Gets a "pages" folder in a `Next.js` application.
    * JavaScript files inside these folders are mapped to routes.
    */
-  Folder getAPagesFolder() {
-    result = pagesRoot()
-    or
-    result = getAPagesFolder().getAFolder()
-  }
+  deprecated predicate getAPagesFolder = pagesFolder/0;
 
   /**
    * Gets a module corrosponding to a `Next.js` page.
    */
-  Module getAPagesModule() { result.getFile().getParentContainer() = getAPagesFolder() }
+  Module getAPagesModule() {
+    result.getFile() = [pagesFolder().getAFile(), appFolder().getJavaScriptFile("page")]
+  }
 
   /**
    * Gets a module inside a "pages" folder where `fallback` from `getStaticPaths` is not set to false.
@@ -300,11 +301,17 @@ module NextJS {
   class NextAppRouteHandler extends DataFlow::FunctionNode, Http::Servers::StandardRouteHandler {
     NextAppRouteHandler() {
       exists(Module mod |
-        mod.getFile().getParentContainer() = apiFolder() or
-        mod.getFile().getStem() = "middleware"
+        (
+          mod.getFile().getParentContainer() = apiFolder()
+          or
+          mod.getFile().getStem() = "middleware"
+          or
+          mod.getFile().getStem() = "route" and mod.getFile().getParentContainer() = appFolder()
+        )
       |
         this =
-          mod.getAnExportedValue([any(Http::RequestMethodName m), "middleware"]).getAFunctionValue()
+          mod.getAnExportedValue([any(Http::RequestMethodName m), "middleware", "proxy"])
+              .getAFunctionValue()
       )
     }
 

javascript/ql/src/change-notes/2025-11-26-nextjs-page-route-files.md

@@ -0,0 +1,5 @@
+---
+category: minorAnalysis
+---
+* Fixed a bug in the Next.js model that would cause the analysis to miss server-side taint sources in files
+  named `route` or `page` appearing outside `api` and `pages` folders.

javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXss.expected

@@ -35,6 +35,9 @@
 | app/api/routeNextRequest.ts:15:20:15:23 | body | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:15:20:15:23 | body | Cross-site scripting vulnerability due to a $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
 | app/api/routeNextRequest.ts:27:20:27:23 | body | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:27:20:27:23 | body | Cross-site scripting vulnerability due to a $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
 | app/api/routeNextRequest.ts:31:27:31:30 | body | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:31:27:31:30 | body | Cross-site scripting vulnerability due to a $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
+| app/blah/page.jsx:8:13:8:19 | req.url | app/blah/page.jsx:8:13:8:19 | req.url | app/blah/page.jsx:8:13:8:19 | req.url | Cross-site scripting vulnerability due to a $@. | app/blah/page.jsx:8:13:8:19 | req.url | user-provided value |
+| app/blah/page.jsx:15:13:15:19 | req.url | app/blah/page.jsx:15:13:15:19 | req.url | app/blah/page.jsx:15:13:15:19 | req.url | Cross-site scripting vulnerability due to a $@. | app/blah/page.jsx:15:13:15:19 | req.url | user-provided value |
+| app/blah/route.ts:3:25:3:27 | url | app/blah/route.ts:2:17:2:23 | req.url | app/blah/route.ts:3:25:3:27 | url | Cross-site scripting vulnerability due to a $@. | app/blah/route.ts:2:17:2:23 | req.url | user-provided value |
 | app/pages/Next2.jsx:8:13:8:19 | req.url | app/pages/Next2.jsx:8:13:8:19 | req.url | app/pages/Next2.jsx:8:13:8:19 | req.url | Cross-site scripting vulnerability due to a $@. | app/pages/Next2.jsx:8:13:8:19 | req.url | user-provided value |
 | app/pages/Next2.jsx:15:13:15:19 | req.url | app/pages/Next2.jsx:15:13:15:19 | req.url | app/pages/Next2.jsx:15:13:15:19 | req.url | Cross-site scripting vulnerability due to a $@. | app/pages/Next2.jsx:15:13:15:19 | req.url | user-provided value |
 | etherpad.js:11:12:11:19 | response | etherpad.js:9:16:9:30 | req.query.jsonp | etherpad.js:11:12:11:19 | response | Cross-site scripting vulnerability due to a $@. | etherpad.js:9:16:9:30 | req.query.jsonp | user-provided value |
@@ -154,6 +157,8 @@ edges
 | app/api/routeNextRequest.ts:4:9:4:12 | body | app/api/routeNextRequest.ts:31:27:31:30 | body | provenance |  |
 | app/api/routeNextRequest.ts:4:16:4:31 | await req.json() | app/api/routeNextRequest.ts:4:9:4:12 | body | provenance |  |
 | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:4:16:4:31 | await req.json() | provenance |  |
+| app/blah/route.ts:2:11:2:13 | url | app/blah/route.ts:3:25:3:27 | url | provenance |  |
+| app/blah/route.ts:2:17:2:23 | req.url | app/blah/route.ts:2:11:2:13 | url | provenance |  |
 | etherpad.js:9:5:9:12 | response | etherpad.js:11:12:11:19 | response | provenance |  |
 | etherpad.js:9:16:9:30 | req.query.jsonp | etherpad.js:9:5:9:12 | response | provenance |  |
 | formatting.js:4:9:4:12 | evil | formatting.js:6:43:6:46 | evil | provenance |  |
@@ -367,6 +372,11 @@ nodes
 | app/api/routeNextRequest.ts:15:20:15:23 | body | semmle.label | body |
 | app/api/routeNextRequest.ts:27:20:27:23 | body | semmle.label | body |
 | app/api/routeNextRequest.ts:31:27:31:30 | body | semmle.label | body |
+| app/blah/page.jsx:8:13:8:19 | req.url | semmle.label | req.url |
+| app/blah/page.jsx:15:13:15:19 | req.url | semmle.label | req.url |
+| app/blah/route.ts:2:11:2:13 | url | semmle.label | url |
+| app/blah/route.ts:2:17:2:23 | req.url | semmle.label | req.url |
+| app/blah/route.ts:3:25:3:27 | url | semmle.label | url |
 | app/pages/Next2.jsx:8:13:8:19 | req.url | semmle.label | req.url |
 | app/pages/Next2.jsx:15:13:15:19 | req.url | semmle.label | req.url |
 | etherpad.js:9:5:9:12 | response | semmle.label | response |

javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXssWithCustomSanitizer.expected

@@ -34,6 +34,9 @@
 | app/api/routeNextRequest.ts:15:20:15:23 | body | Cross-site scripting vulnerability due to $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
 | app/api/routeNextRequest.ts:27:20:27:23 | body | Cross-site scripting vulnerability due to $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
 | app/api/routeNextRequest.ts:31:27:31:30 | body | Cross-site scripting vulnerability due to $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
+| app/blah/page.jsx:8:13:8:19 | req.url | Cross-site scripting vulnerability due to $@. | app/blah/page.jsx:8:13:8:19 | req.url | user-provided value |
+| app/blah/page.jsx:15:13:15:19 | req.url | Cross-site scripting vulnerability due to $@. | app/blah/page.jsx:15:13:15:19 | req.url | user-provided value |
+| app/blah/route.ts:3:25:3:27 | url | Cross-site scripting vulnerability due to $@. | app/blah/route.ts:2:17:2:23 | req.url | user-provided value |
 | app/pages/Next2.jsx:8:13:8:19 | req.url | Cross-site scripting vulnerability due to $@. | app/pages/Next2.jsx:8:13:8:19 | req.url | user-provided value |
 | app/pages/Next2.jsx:15:13:15:19 | req.url | Cross-site scripting vulnerability due to $@. | app/pages/Next2.jsx:15:13:15:19 | req.url | user-provided value |
 | formatting.js:6:14:6:47 | util.fo ... , evil) | Cross-site scripting vulnerability due to $@. | formatting.js:4:16:4:29 | req.query.evil | user-provided value |

javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/blah/page.jsx

@@ -0,0 +1,19 @@
+export default function Page() {
+    return <span />;
+}
+
+Page.getInitialProps = async (ctx) => {
+    const req = ctx.req;
+    const res = ctx.res;
+    res.end(req.url); // $ Alert
+    return {}
+}
+
+export async function getServerSideProps(ctx) {
+    const req = ctx.req;
+    const res = ctx.res;
+    res.end(req.url); // $ Alert
+    return {
+        props: {}
+    }
+}

javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/blah/route.ts

@@ -0,0 +1,4 @@
+export async function GET(req: Request) {
+    const url = req.url; // $ Source
+    return new Response(url, { headers: { "Content-Type": "text/html" } }); // $ Alert
+}