What an update actually changes
Software is written by people, and large programs contain mistakes. Some of those mistakes are security flaws, also called vulnerabilities. They might let an attacker run code on your device, read information they should not see, or bypass a protection. When developers find or are told about such a flaw, they release a fix, commonly called a patch, usually inside a regular update.
Not every update is about security. Many add features or fix ordinary bugs. But security fixes are often bundled in with them, and the release notes do not always spell out the details, partly because publishing a full description of a flaw before most people have patched could help attackers.
How known flaws get exploited
Here is the part that makes delay risky. Once a patch is released, the flaw it fixes is effectively public knowledge. Attackers can study the patch to work out what was wrong, and then scan for devices that have not applied it. Automated tools can try this against huge numbers of devices at once, so you do not need to be a particular target to be hit. You just need to be unpatched.
A typical sequence is:
- A flaw is found in a widely used program.
- A fix is released.
- Attackers learn from the fix how to take advantage of the flaw.
- People who delay updating become easier to attack than people who updated.
Some flaws are exploited before a patch exists. These are often called zero-day vulnerabilities. You cannot do much about those directly, but the more quickly you install the eventual fix, the shorter your window of exposure.
Many malware infections begin with this kind of weakness, such as a web page or file that takes advantage of an old flaw in a browser or document reader. Understanding that connection can help when you read about malware removal.
What needs updating
It is easy to think only of the computer and phone. In practice, the list is longer:
- Operating systems on phones, tablets and computers.
- Web browsers and their extensions, since browsers handle untrusted content all day.
- Apps and programs, especially those that open files or connect to the internet.
- Your home router, which sits between your devices and the internet. Some routers update automatically, and others need a manual check. See network basics and home Wi-Fi for how it fits into your setup.
- Smart devices such as cameras, speakers and thermostats. Smart device security often comes down to whether the maker still releases updates.
- Firmware on things like printers and game consoles.
Practical ways to stay current
Turn on automatic updates
This is usually the single most effective step. Most operating systems, browsers and app stores have a setting that installs updates in the background or overnight. Automatic updates remove the need to remember anything.
Restart when asked
Some updates only take effect after a restart. If your device keeps asking, and you keep postponing, the fix may be sitting unused. Choose a time that suits you, such as the end of the day, and let it finish.
Check manually for things that do not update themselves
Routers, older smart devices and rarely used apps may need a periodic visit. A calendar reminder every few months is enough for most people.
Use official sources only
Download updates through the system’s built-in update tool, the official app store or the developer’s website. Pop-ups or emails urging you to “update now” with a link are a common trick, and some phishing emails imitate update notices. If a message claims you need an update, open the settings yourself instead of clicking.
Remove what you do not use
Every installed program is one more thing that may need patching. Uninstalling apps you have not opened in a year reduces the number of places a flaw can hide.
When support ends
Software and devices do not receive updates forever. When a maker stops supporting a product, new flaws are no longer fixed, and over time that product becomes riskier. If a device you rely on reaches that point, consider replacing it, or limit what you use it for, avoiding sensitive logins and shopping. Check the maker’s support information to learn how long updates are expected to continue, and keep in mind that this varies widely.
Concerns people have
“Updates sometimes break things.” Occasionally they do, and that is a fair concern. A reasonable approach is to keep a backup, so a problem can be reversed. Having a sound backup strategy makes updating less stressful. For most individuals, the risk of staying unpatched outweighs the risk of an occasional glitch.
“My device is old and slow.” Updates can sometimes change performance, but if the device is still supported, keeping it patched is usually still worthwhile. If it is no longer supported, see the section above.
“I do not have anything worth stealing.” Attackers often want your device itself, your accounts or your identity, not specific files. An unpatched device can be used to send spam, mine for passwords or attack others.
Updates are not a complete defense. They work best alongside unique passwords, a second sign-in step and sensible caution with messages. But because they close known holes for free, with very little effort once automated, they are among the best returns on your time in personal security.