Apple has released out-of-band security patches to address a critical iOS, macOS, watchOS, and Safari web browser to address a security flaw tracked as CVE-2021-1844.

The vulnerability was discovered by Clément Lecigne of Google’s Threat Analysis Group and Alison Huffman of Microsoft Browser Vulnerability Research. The flaw could be exploited by remote attackers to run arbitrary code on vulnerable devices by tricking users into visiting a malicious web content.

The vulnerability is caused by a memory corruption issue that could be triggered to cause arbitrary code execution when processing specially crafted web content.

“Processing maliciously crafted web content may lead to arbitrary code execution.” reads the advisory published by Apple. “Description: A memory corruption issue was addressed with improved validation.”

Apple has improved validation to address the vulnerability.

Apple has released an update for devices running iOS 14.4, iPadOS 14.4macOS Big Sur, and watchOS 7.3.1 (Apple Watch Series 3 and later). Apple also released an update to Safari for MacBooks running macOS Catalina and macOS Mojave.

In March, Pwn20wnd, the author of the jailbreaking tool “unc0ver,” has updated their software to support iOS 14.3 and earlier releases. The last release of the jailbreaking tool, unc0ver v6.0.0, now includes the exploit code for the CVE-2021-1782 vulnerability that Apple in January claimed was actively exploited by threat actors. The CVE-2021-1782 flaw is a race condition issue that resides in the iOS operating system kernel.