CVE-2021-21100: 
Adobe Digital Editions vulnerability analysis and mitigation

Adobe Digital Editions version 4.5.11.187245 (and earlier) is affected by a Privilege Escalation vulnerability during installation that was discovered in December 2020. The vulnerability allows an unauthenticated attacker to achieve arbitrary file system write in the context of the current user (CVE Mitre, NVD).

The vulnerability is classified as a Privilege Escalation issue that occurs during the installation process of Adobe Digital Editions. It enables arbitrary file system write capabilities, which could lead to unauthorized system modifications. Exploitation requires user interaction, specifically requiring a victim to open a malicious file (Adobe Security).

If successfully exploited, the vulnerability allows an attacker to write arbitrary files to the system with the privileges of the current user. This could potentially lead to system compromise through unauthorized file modifications (Threatpost).

Adobe has released patches to address this vulnerability in Adobe Digital Editions. Users are advised to update to the latest version of the software to mitigate the risk (Adobe Security).

The vulnerability was acknowledged as critical by Adobe, and security researchers noted it as part of Adobe's April 2021 security updates. Adobe credited Qingyang Chen of Topsec for discovering the vulnerability (Threatpost).