Sunrise calendar for iPhone users received an email late last night detailing the effects of a cyber attack last week on MongoHQ, the company's database provider. Sunrise CEO Pierre Valade assured users that all of their data and credentials are safe, with the exception of their iCloud calendar data, which could've potentially been compromised. He recommends that users change their iCloud password if they were using Sunrise's recently added iCloud calendar sync feature.

A sobering reminder of the risks to using cloud apps like Sunrise or Mailbox to sync your most sensitive data

Earlier this week, social media app Buffer was hit by the same hack, since it also uses MongoHQ. Hackers posted spam tweets and posts from customers accounts, since Buffer stored users' Twitter and Facebook log-in tokens in its database, unencrypted. The hacking is a sobering reminder of the risks to using cloud apps like Sunrise or Mailbox to sync your most sensitive data. Apps like Fantastical or iOS Mail, on the other hand, communicate directly with Apple and Google without any middleman to fetch or cache data.