CVE-2021-1873: 
macOS vulnerability analysis and mitigation

CVE-2021-1873 is a security vulnerability discovered in Apple's macOS operating systems affecting the WindowServer component. The vulnerability was disclosed and patched in April 2021, affecting macOS Big Sur, Catalina, and Mojave versions. The issue involves an API vulnerability in Accessibility TCC (Transparency, Consent, and Control) permissions that could allow malicious applications to unexpectedly leak user credentials from secure text fields (Apple Advisory).

The vulnerability stems from an API issue in Accessibility TCC permissions within the WindowServer component. The technical root cause was identified as a state management problem that could be exploited to leak credentials from secure text fields. Apple addressed this vulnerability by implementing improved state management in the affected systems. The vulnerability has been assigned a CVSS v3.1 base score of 6.5 (Medium), with a vector string of CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N (NVD).

The vulnerability allows a malicious application to unexpectedly leak a user's credentials from secure text fields. This could potentially expose sensitive user information to unauthorized applications, compromising user security and privacy (Apple Advisory).

Apple has released security updates to address this vulnerability in multiple macOS versions: macOS Big Sur 11.3, Security Update 2021-002 Catalina, and Security Update 2021-003 Mojave. Users are advised to update their systems to these versions to protect against potential exploitation (Apple Advisory, Apple Catalina, Apple Mojave).