On February 17, 2017, the "Cloudbleed" security bug was discovered. This bug affected Cloudflare's CDN product, which is used by millions of websites. For any websites that use Cloudflare, it is possible that users' private data may have been exposed to the public, including passwords, personally identifiable information, credit card numbers, etc. That data was also stored in search engine caches for some time after the bug was discovered, greatly amplifying the impact of this bug. Read more about Cloudbleed on Wikipedia.
We take web and information security extremely seriously at Vector. To better help the public determine if they were affected by this bug, we built and released the Cloudflare Vulnerability History Analyzer. This free and open source Mac app will scan your Chrome browsing history and determine if any of the sites you've visited are using Cloudflare. If there are any matches, we strongly recommend you change your passwords on those sites, and reevaluate if they are storing any other sensitive or private information.
If you're concerned about your web security, feel free to get in touch!