Prevent successful validation Pin with a specially crafted Post-request

[wwwcase]

undefined != undefined is false !!!! in login.js exports.VerifyPin = function(req, res) { var queryData = url.parse(req.url, true).query; if (!req.body || !req.body['pin'] || !req.body['pin'].length || !queryData.user || !emailChecker[queryData.user] ) return LoginError(req, res, 'ERROR: Bad PIN!');

const check = emailChecker[queryData.user];
delete emailChecker[queryData.user]; //if (check.pin != req.body['pin']) // not properly if ( !check.pin || !req.body['pin'] || (check.pin != req.body['pin']) ) // correctly return LoginError(req, res, 'ERROR: Not verified!');

Login(req, res, check.info); }