CVE-2021-30719: 
macOS vulnerability analysis and mitigation

CVE-2021-30719 is a security vulnerability discovered in Apple's macOS operating systems affecting the Intel Graphics Driver component. The vulnerability was disclosed and patched in May 2021 as part of macOS Big Sur 11.4 and Security Update 2021-003 Catalina releases. The issue was identified as an out-of-bounds read vulnerability in the AppleIntelKBLGraphics kernel extension that could allow a local user to cause unexpected system termination or read kernel memory (Apple Support, ZDI Advisory).

The vulnerability exists within the handling of IOCTL 0x20006 in the AppleIntelKBLGraphics kernel extension. The specific flaw stems from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. The vulnerability has been assigned a CVSS v3.1 base score of 7.1 (HIGH) with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H (NVD, ZDI Advisory).

The vulnerability allows local attackers to disclose sensitive information from kernel memory and potentially cause system termination. An attacker must first obtain the ability to execute low-privileged code on the target system to exploit this vulnerability. The issue could potentially be leveraged in conjunction with other vulnerabilities to escalate privileges and execute code in the context of the kernel (ZDI Advisory).

Apple addressed this vulnerability by removing the vulnerable code in macOS Big Sur 11.4 and Security Update 2021-003 Catalina, released on May 24, 2021. Users should update to these or later versions to protect against this vulnerability (Apple Support, Apple Support).