CVE-2021-21017

Name: CVE-2021-21017
Creator: NVD / NIST
Published: 2021-02-11T20:15:13.997+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10Actively ExploitedEPSS 86.21%

Last modified Jun 17, 2026

CVE-2021-21017 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 86.21% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

86.21%

99.7th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Adobe	Acrobat	>= 17.0, <= 17.011.30188
Adobe	Acrobat	>= 20.0, <= 20.001.30018
Adobe	Acrobat Dc	<= 20.013.20074
Adobe	Acrobat Reader	>= 17.0, <= 17.011.30188
Adobe	Acrobat Reader	>= 20.0, <= 20.001.300183
Adobe	Acrobat Reader Dc	<= 20.013.20074

References

https://helpx.adobe.com/security/products/acrobat/apsb21-09.htmlVendor Advisory
https://helpx.adobe.com/security/products/acrobat/apsb21-09.htmlVendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21017Third Party Advisory, US Government Resource

Timeline

Published: Feb 11, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-21017?

How severe is CVE-2021-21017?

CVE-2021-21017 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 86.21% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-21017?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21017?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST