CVE-2021-30713: 
macOS vulnerability analysis and mitigation

CVE-2021-30713 is a permissions vulnerability in Apple's Transparency, Consent, and Control (TCC) framework that affects macOS Big Sur versions prior to 11.4. The vulnerability was discovered and reported by an anonymous researcher and was confirmed to be actively exploited in the wild. The issue allowed malicious applications to bypass Privacy preferences without requiring explicit user consent (Apple Advisory, Help Net Security).

The vulnerability exists in Apple's TCC framework, which controls what resources applications have access to on macOS systems. The issue stems from a permissions validation problem that allows malicious applications to inherit permissions from donor applications. Specifically, the exploit involves using an AppleScript module to search for applications with existing permissions and then compiling a custom AppleScript application that gets injected into the donor application, thereby bypassing the normal permission prompts (Help Net Security).

The vulnerability allows malicious applications to bypass Privacy preferences and gain unauthorized access to protected system resources. This could enable attackers to capture screenshots of the user's desktop and potentially gain access to other sensitive permissions that have already been granted to legitimate applications without user consent (Help Net Security).

Apple addressed this vulnerability in macOS Big Sur 11.4 by improving validation in the TCC framework. Users are advised to update their systems to this version or later to protect against this vulnerability (Apple Advisory).