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fix(apps): prevent open redirect via backslash manipulation in Host header #3740

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Merged
alan-agius4 merged 1 commit into from
Jun 5, 2026
Merged

fix(apps): prevent open redirect via backslash manipulation in Host header #3740

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10 changes: 10 additions & 0 deletions apps/functions/dns-redirecting/index.ts
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Original file line number Diff line number Diff line change
@@ -1,5 +1,10 @@
import * as functions from 'firebase-functions';

const isValidDomain = (domain: string): boolean => {
// Only allow alphanumeric characters, dots, and hyphens
return /^[a-zA-Z0-9.-]+$/.test(domain);
};
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josephperrott marked this conversation as resolved.

export const dnsRedirecting = functions.https.onRequest(
{
cors: true,
Expand Down Expand Up @@ -30,6 +35,11 @@ export const dnsRedirecting = functions.https.onRequest(
}
}

if (!isValidDomain(hostname)) {
response.status(400).send('Invalid Hostname');
return;
}

if (hostname === 'code-of-conduct.angular.io') {
response.redirect(redirectType, 'https://code-of-conduct.angular.dev');
} else if (hostname === 'update.angular.dev') {
Expand Down
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