CVE-2021-21042: 
Adobe Acrobat Reader Continuous vulnerability analysis and mitigation

CVE-2021-21042 affects Acrobat Reader DC versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier), and 2017.011.30188 (and earlier). This vulnerability is classified as an Out-of-bounds Read vulnerability that could lead to arbitrary disclosure of information in the memory stack (NVD, CVE).

The vulnerability is classified as an Out-of-bounds Read issue with a CVSS v3.1 Base Score of 6.5 (Medium) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N. The vulnerability could allow an attacker to bypass security mitigations such as Address Space Layout Randomization (ASLR). The exploitation requires user interaction, specifically opening a malicious file (NVD).

If successfully exploited, this vulnerability could lead to arbitrary disclosure of information in the memory stack and enable attackers to bypass security mitigations such as ASLR. The vulnerability primarily affects the confidentiality of the system, with no direct impact on integrity or availability (NVD).

The vulnerability requires user interaction for successful exploitation, specifically requiring a victim to open a malicious file. The attack vector is network-based (AV:N) with low attack complexity (AC:L) and requires no privileges (PR:N) (NVD).

Adobe has released security updates to address this vulnerability. Users should update to the latest version of Adobe Acrobat and Reader as detailed in the security bulletin APSB21-09 (Adobe Advisory).