CVE-2021-21017
Acrobat Reader DC Heap-based Buffer Overflow Vulnerability Could Lead To Arbitrary Code Execution
- Published
- Feb 11, 2021
- Updated
- Oct 21, 2025
- Assigning CNA
- adobe
- Evidence observed
- Nov 3, 2021
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HHigh · next 30 days
- Percentile
- 99.7%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
CISA Known Exploited
This CVE appears in the CISA Known Exploited Vulnerabilities catalog.
Summary
Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by a heap-based buffer overflow vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
Sources
2Proof-of-concept exploit for CVE-2021-21017, an Adobe Reader type confusion leading to out-of-bounds read and heap overflow, with technical analysis and detection guidance.
Proof-of-concept exploit for Adobe Reader type confusion leading to heap overflow, with detailed root-cause analysis and detection guidance.
Responsible use
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