Acrobat Reader DC versions 2021.005.20054 (and earlier), 2020.004.30005 (and earlier) and 2017.011.30197 (and earlier) are affected by an out-of-bounds read vulnerability. An unauthenticated attacker could leverage this vulnerability achieve arbitrary read / write system information in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.