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Potential fix for code scanning alert no. 4: Uncontrolled data used in path expression #4

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Merged
scottsgeorge merged 1 commit into from
Dec 24, 2025
Merged

Potential fix for code scanning alert no. 4: Uncontrolled data used in path expression #4

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17 changes: 15 additions & 2 deletions scripts/serve.js
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Original file line number Diff line number Diff line change
Expand Up @@ -25,8 +25,21 @@ const mimeTypes = {

const server = http.createServer((req, res) => {
const parsedUrl = url.parse(req.url);
const safePath = path.normalize(parsedUrl.pathname || '/').replace(/^\.\.(\/|\\)/, '');
let pathname = path.join(rootDir, safePath);
// Normalize the requested path and ensure it is relative
let safePath = path.normalize(parsedUrl.pathname || '/');
// Remove any leading slashes to force a path relative to rootDir
safePath = safePath.replace(/^([/\\])+/, '');

// Resolve the final pathname within rootDir
let pathname = path.resolve(rootDir, safePath || 'index.html');

// Ensure the resolved path is within the root directory
const rootWithSep = rootDir.endsWith(path.sep) ? rootDir : rootDir + path.sep;
if (pathname !== rootDir && !pathname.startsWith(rootWithSep)) {
res.statusCode = 403;
res.end('Forbidden');
return;
}

if (fs.existsSync(pathname) && fs.statSync(pathname).isDirectory()) {
pathname = path.join(pathname, 'index.html');
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