From drones to smartphone apps, Indonesia is harnessing technology to tackle traffic chaos during the annual mass exodus before the Muslim Eid holiday, when the potholed roads of overpopulated Java become clogged with millions of slow-moving cars and crashes are frequent.

Cities in the world's most populous Muslim-majority country empty every year at the end of the holy month of Ramadan as people head to villages to celebrate Eid with their families. 

Indonesian divers on Tuesday retrieved the cockpit voice recorder from beneath the wreckage of an AirAsia plane that crashed into the Java Sea as the airline's boss vowed to overcome the "toughest times" he has known.

It came a day after the plane's other black box, the flight data recorder, was recovered, and the devices should provide investigators with vital information about what caused the accident.

Torrential downpours triggered a landslide on Indonesia's main island of Java, killing at least 17 people and leaving nearly 100 others missing, with persistent rain hampering rescue efforts, officials said Saturday.

Hundreds of rescuers were digging with shovels through mud and rubble after the landslide buried scores of houses in Jemblung village in central Java late Friday, the national disaster agency said.

Oracle on Monday was distributing a patch for Java software flaws deemed so dangerous that the U.S. Department of Homeland Security said that people should stop using it.

"Oracle recommends that this Security Alert be applied as soon as possible because these issues may be exploited 'in the wild' and some exploits are available in various hacking tools," Oracle's Eric Maurice said in a blog post.

The U.S. Department of Homeland Security warned Thursday that a flaw in Java software is so dangerous that people should stop using it.

"This vulnerability is being attacked in the wild, and is reported to be incorporated into exploit kits," the department's Computer Emergency Readiness Team said in a notice on its website.