Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by an Out-of-bounds Read vulnerability. An unauthenticated attacker could leverage this vulnerability to locally escalate privileges in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-21042
• https://helpx.adobe.com/security/products/acrobat/apsb21-09.html