Snapchat has released an update to its popular photo-sharing app, aimed at patching a security flaw that left users’ names and phone numbers exposed.

The update was accompanied by a post on the company blog explaining the patch, which tweaks the “Find Friends” tool that had been the source of the problem.

The new version of Snapchat allows users to more easily hide their phone numbers, making them less vulnerable to hackers. It is also supposed to fortify security around Snapchat’s Application Programming Interface (API), essentially the front door to the app’s internal workings.

Read the blog: “Our team continues to make improvements to the Snapchat service to prevent future attempts to abuse our API. We are sorry for any problems this issue may have caused you and we really appreciate your patience and support.”

The post also marks the first apology from the company since the security flaw became public on Christmas Day. Some observers have been troubled by the apparent lack of contrition shown by Evan Spiegel, Snapchat’s 23-year-old co-founder and chief executive, throughout the ordeal.

The Venice company makes a messaging app that lets people share photos and videos that have a built in self-destruct feature. Its popularity – more than 350 million photos are shared a day through the service – has given rise to a new category of ephemeral messaging apps and has pushed Snapchat’s valuation skyward. The company reportedly turned down a $3 billion acquisition offer from Facebook Chief Executive Mark Zuckerberg in November.

In August, a hacking group warned the company its users’ phone numbers were vulnerable through a flaw in Find Friends. The tool requires users to enter their phone number into a database, creating a searchable directory where you can find friends based on the numbers in your address book.