A use-after-free vulnerability exists in the way certain events are processed for ImageLoader objects of Webkit WebKitGTK 2.30.4. A specially crafted web page can lead to a potential information leak and further memory corruption. In order to trigger the vulnerability, a victim must be tricked into visiting a malicious webpage.

This issue was addressed with improved iframe sandbox enforcement. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. Maliciously crafted web content may violate iframe sandboxing policy.

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

A port redirection issue was addressed with additional port validation. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. A malicious website may be able to access restricted ports on arbitrary servers.

"Clear History and Website Data" did not clear the history. The issue was addressed with improved data deletion. This issue is fixed in macOS Big Sur 11.1, Security Update 2020-001 Catalina, Security Update 2020-007 Mojave, iOS 14.3 and iPadOS 14.3, tvOS 14.3. A user may be unable to fully delete browsing history.

This issue was addressed with improved iframe sandbox enforcement. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. Maliciously crafted web content may violate iframe sandboxing policy.

A code execution vulnerability exists in the AudioSourceProviderGStreamer functionality of Webkit WebKitGTK 2.30.1. A specially crafted web page can lead to a use after free.

A use after free issue was addressed with improved memory management. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 14.2 and iPadOS 14.2, iCloud for Windows 11.5, Safari 14.0.1, tvOS 14.2, iTunes 12.11 for Windows. Processing maliciously crafted web content may lead to arbitrary code execution.

An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.1 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in a remote code execution. The victim needs to visit a malicious web site to trigger this vulnerability.

An input validation issue was addressed with improved input validation. This issue is fixed in iOS 14.0 and iPadOS 14.0, tvOS 14.0, watchOS 7.0, Safari 14.0, iCloud for Windows 11.4, iCloud for Windows 7.21. Processing maliciously crafted web content may lead to a cross site scripting attack.