SEOUL - A South Korean child-monitoring smartphone app that was removed from the market in 2015 after it was found to be riddled with security flaws has been reissued under a new name and still puts children at risk, researchers said on Monday.

The "Cyber Security Zone" app is part of government efforts to curb what authorities consider excessive cell phone use by young people. Parents are required by law to install monitoring software on smartphones for all children 18 and under.

The app is almost identical to a previous system, "Smart Sheriff", which left children's private information vulnerable to hackers, said internet watchdog Citizen Lab at the University of Toronto. Both were developed under the auspices of MOIBA, the industry association for South Korean cell phone service providers.