Zero-day vulnerability in macOS

Input validation error
CVE-2021-30713

Known malware:

XCSSET

Vulnerability details

Advisory: SB2021052415 - Multiple vulnerabilities in Apple macOS Big Sur

Vulnerable component: macOS

CVE-ID: CVE-2021-30713

CVSSv3 score: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:H/RL:O/RC:C

CWE-ID: CWE-20 - Improper input validation

Description:

The vulnerability allows a local user to bypass Privacy preferences.

The vulnerability exists due to insufficient validation of user-supplied input within the TCC subsystem. A malicious application can  bypass Privacy preferences and gain full disk access, perform screen recording or gain other permissions without requiring user's explicit consent.

Note, the vulnerability is being actively exploited in the wild by XCSSET malware.

External links:

https://support.apple.com/en-us/HT212529
https://www.jamf.com/blog/zero-day-tcc-bypass-discovered-in-xcsset-malware/

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.