Here's why you need to update your iPhone now, and how to do it

Security flaws prompt Apple to issue iOS update

If you use an iPhone, there's something you need to know.

IPhone users are getting another alert for Apple's latest version of its mobile operating system. But cybersecurity experts are urging consumers not to ignore this update, which fixes an unprecedented type of security flaw.

Who's eligible

Owners of iPhone 4s and later, iPad 2 and later, iPod touch (5th generation) and later can get this update, according to Apple's support website. You should be automatically notified that it's available, or you can update manually using iTunes.

Why it matters

Apple released iOS 9.3.5 on Thursday to patch three security vulnerabilities, believed to have been used by "digital arms dealers" to spy on dissidents and journalists, according to The New York Times. Apple's patch targets previously unknown spyware that infiltrated iPhones and can read messages, track calls and contacts, record sounds, collect passwords and location information, investigators told the Times.

The discovery of the hack is chilling in itself. But what users really need to know is how to make sure they have the latest, safest version on their iPhones.

How to update

Here are Apple's instructions on how to update, from Apple's support page:

Before you update

Make a backup of your device using iCloud or iTunes.

Update your device wirelessly

If a message says that an update is available, tap Install Now. You can also follow these steps:

1. Plug your device into power and connect to the Internet with Wi-Fi.

2. Tap Settings > General > Software Update.

3. Tap Download and Install. If a message asks to temporarily remove apps because iOS needs more space for the update, tap Continue or Cancel. Later, iOS will reinstall apps that it removed. If you tap Cancel, learn what to do next.

4. To update now, tap Install. Or you can tap Later and choose Install Tonight or Remind Me Later. If you tap Install Tonight, just plug your iOS device into power before you go to sleep. Your device will update automatically overnight.

5. If asked, enter your passcode. If you don't know your passcode, learn what to do.

If you see an error or need more space when updating wirelessly.

If you see an error message while trying to update your device wirelessly, learn what to do. If you need more space for a wireless update, you can update using iTunes or delete content manually from your device. Whether you use iTunes or update wirelessly, you'll have the same amount of free space on your device after you update.

Some iOS software updates aren't available wirelessly. VPN or proxy connections might prevent your device from contacting the iOS update servers.

Update your device using iTunes

If you can't update wirelessly on your iOS device, you can update manually using iTunes on a computer that you trust. If your computer is using Personal Hotspot on the iOS device that you're updating, connect your computer to a different WiFi or Ethernet network before you update.

1. Install the latest version of iTunes on your computer.

2. Connect your device to your computer.

3. Open iTunes and select your device.

4. Click Summary, then click Check for Update.

5. Click Download and Update.

If you see error messages in iTunes or need more space to update

Get help if you see error messages while updating your device with iTunes. Or if you need more space for an update, you can delete content from your device manually.

Make space for that update

Yes, it's painful, but you may need to take the time to back up or sift through less-used apps and photos to make room. Apple has some tips on its website, and some other publications do to.

Check out the links below.

Apple Support: If you need more space for an iOS update

NY Mag: Basic Answers to Basic Questions: How to Free Up Space on Your iPhone

USA Today: This trick can free up space on your iPhone