An independent cybersecurity researcher has come up with a short CSS that can force Apple iOS devices to do a full restart.

The researcher, who tweets under the name Sabri, posted the 15-lines of code needed to exploit the flaw to Github on Sept. 15. In addition to affecting iOS devices the CSS can also force Safari to hang, but otherwise, it is benign and cannot be used as an avenue of attack Sabri said on Twitter.

The code exploits a flaw in the iOS' Webkit.

Sabri told TechCrunch, “that nesting a ton of elements — such as <div> tags — inside a backdrop filter property in CSS, you can use up all of the device’s resources and cause a kernel panic, which shuts down and restarts the operating system to prevent damage.”

The restart can be activated by intentionally running the code on the device or having someone send a link to a site with the code or an email, he told TechCrunch.