fix: MFA recovery codes not consumed after use ([GHSA-4hf6-3x24-c9m8](https://github.com/parse-community/parse-server/security/advisories/GHSA-4hf6-3x24-c9m8)) (#10170)

spec/AuthenticationAdapters.spec.js

@@ -1913,6 +1913,60 @@ describe('OTP TOTP auth adatper', () => {
     );
   });
 
+  it('consumes recovery code after use', async () => {
+    const user = await Parse.User.signUp('username', 'password');
+    const OTPAuth = require('otpauth');
+    const secret = new OTPAuth.Secret();
+    const totp = new OTPAuth.TOTP({
+      algorithm: 'SHA1',
+      digits: 6,
+      period: 30,
+      secret,
+    });
+    const token = totp.generate();
+    await user.save(
+      { authData: { mfa: { secret: secret.base32, token } } },
+      { sessionToken: user.getSessionToken() }
+    );
+    // Get recovery codes from stored auth data
+    await user.fetch({ useMasterKey: true });
+    const recoveryCode = user.get('authData').mfa.recovery[0];
+    // First login with recovery code should succeed
+    await request({
+      headers,
+      method: 'POST',
+      url: 'http://localhost:8378/1/login',
+      body: JSON.stringify({
+        username: 'username',
+        password: 'password',
+        authData: {
+          mfa: {
+            token: recoveryCode,
+          },
+        },
+      }),
+    });
+    // Second login with same recovery code should fail (code consumed)
+    await expectAsync(
+      request({
+        headers,
+        method: 'POST',
+        url: 'http://localhost:8378/1/login',
+        body: JSON.stringify({
+          username: 'username',
+          password: 'password',
+          authData: {
+            mfa: {
+              token: recoveryCode,
+            },
+          },
+        }),
+      }).catch(e => {
+        throw e.data;
+      })
+    ).toBeRejectedWith({ code: Parse.Error.SCRIPT_FAILED, error: 'Invalid MFA token' });
+  });
+
   it('future logins reject incorrect TOTP token', async () => {
     const user = await Parse.User.signUp('username', 'password');
     const OTPAuth = require('otpauth');

src/Adapters/Auth/mfa.js

@@ -39,6 +39,8 @@
  *   - Requires a secret key for setup.
  *   - Validates the user's OTP against a time-based one-time password (TOTP) generated using the secret key.
  *   - Supports configurable digits, period, and algorithm for TOTP generation.
+ *   - Generates two single-use recovery codes during enrollment. Each recovery code can be used once
+ *     in place of a TOTP token and is consumed after use.
  *
  * ## MFA Payload
  * The adapter requires the following `authData` fields:
@@ -157,8 +159,13 @@ class MFAAdapter extends AuthAdapter {
       if (!secret) {
         return saveResponse;
       }
-      if (recovery[0] === token || recovery[1] === token) {
-        return saveResponse;
+      const recoveryIndex = recovery?.indexOf(token) ?? -1;
+      if (recoveryIndex >= 0) {
+        const updatedRecovery = [...recovery];
+        updatedRecovery.splice(recoveryIndex, 1);
+        return {
+          save: { ...auth.mfa, recovery: updatedRecovery },
+        };
       }
       const totp = new TOTP({
         algorithm: this.algorithm,