Adobe Digital Editions version 4.5.11.187245 (and earlier) is affected by a Privilege Escalation vulnerability during installation. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary file system write in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
https://helpx.adobe.com/security/products/Digital-Editions/apsb21-26.html