CVE-2021-21017: Adobe Acrobat and Reader Heap-based Buffer Overflow Vulnerability

CISA Known Exploited Vulnerabilities

Name

Adobe Acrobat and Reader Heap-based Buffer Overflow Vulnerability

Vendor

Adobe

Product

Acrobat and Reader

Added to the catalog

2021-11-03

Due date for US federal agencies

2021-11-17

Weaknesses

CWE-122

Catalog version

2026.10.30

Acrobat Acrobat and Reader contain a heap-based buffer overflow vulnerability that could allow an unauthenticated attacker to achieve code execution in the context of the current user.

Required action (CISA)

Apply updates per vendor instructions.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://nvd.nist.gov/vuln/detail/CVE-2021-21017

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2021-02-11T20:15:13.997

Last modified

2026-06-17T03:34:40.193

Weaknesses

CWE-122, CWE-787

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.

References

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

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-21017

CVE record

Title (CNA)

Acrobat Reader DC Heap-based Buffer Overflow Vulnerability Could Lead To Arbitrary Code Execution

Assigner

adobe

State

PUBLISHED

Published

2021-02-11T19:42:20.225Z

Updated

2025-10-21T23:35:28.186Z

Problem types

Heap-based Buffer Overflow (CWE-122)

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.

References

• https://helpx.adobe.com/security/products/acrobat/apsb21-09.html

Read on 2026-11-03T01:05:53.565Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/21xxx/CVE-2021-21017.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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