Understanding Patches

When vendors become aware of vulnerabilities in their products, they often issue patches to fix the problem. Make sure to apply relevant patches to your computer as soon as possible so that your system is protected.

What are patches?

Similar to the way fabric patches are used to repair holes in clothing, software patches repair holes in software programs. Patches are updates that fix a particular problem or vulnerability within a program. Sometimes, instead of just releasing a patch, vendors will release an upgraded version of their software, although they may refer to the upgrade as a patch.

How do you find out what patches you need to install?

When patches are available, vendors usually put them on their websites for users to download. It is important to install a patch as soon as possible to protect your computer from attackers who would take advantage of the vulnerability. Attackers may target vulnerabilities for months or even years after patches are available. Some software will automatically check for updates, and many vendors offer users the option to receive automatic notification of updates through a mailing list. If these automatic options are available, we recommend that you take advantage of them. If they are not available, check your vendors' websites periodically for updates.

Make sure that you only download software or patches from websites that you trust. Do not trust a link in an email message--attackers have used email messages to direct users to malicious websites where users install viruses disguised as patches. Also, beware of email messages that claim that they have attached the patch to the message--these attachments are often viruses.

Produced by US-CERT.