CVE-2021-21040: 
Adobe Acrobat Reader Continuous vulnerability analysis and mitigation

Acrobat Reader DC versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by a Use After Free vulnerability. This vulnerability was discovered and disclosed in February 2021, affecting multiple versions of Adobe Acrobat and Reader software (CVE Details).

The vulnerability is classified as a Use After Free (CWE-416) issue that could lead to arbitrary code execution. It has received a CVSS v3.1 Base Score of 7.8 (HIGH) with the vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, indicating significant potential impact (NVD).

If successfully exploited, this vulnerability allows an unauthenticated attacker to achieve arbitrary code execution in the context of the current user. The exploitation could potentially compromise the system's confidentiality, integrity, and availability (Qualys Research).

Exploitation of this vulnerability requires user interaction, specifically requiring a victim to open a malicious file. The attack complexity is considered low, but requires local access and user interaction to be successful (NVD).

Adobe has released security updates to address this vulnerability. Users are advised to update to the latest version of the software as detailed in Adobe's security bulletin APSB21-09 (Adobe Advisory).