CVE-2021-21017

8.8 HIGH 86% exploit odds exploited in the wild Fix listed Memory safety

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.
In the wild: CISA lists this as exploited in real attacks. Treat as urgent.
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2020-12-18 00:00 UTC ReservedThe CVE id was reserved by its CNA
2021-02-11 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2021-11-03 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
2021-11-17 Remediation deadlineCISA's due date for federal agencies to fix it
2026-06-17 03:34 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: yes, CISA lists it. This puts it above everything that is not.
Exploit odds: 86.3% in the next 30 days (EPSS).
Severity: 8.8 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2021-02-11 20:15 UTC
Last modified: 2026-06-17 03:34 UTC
Added to CISA KEV: 2021-11-03
Exploit probability: 86.3% · EPSS, next 30 days
Weakness: CWE-122
Record status: Analyzed

Affected

Adobe Acrobat ≤ 17.011.30188
Adobe Acrobat ≤ 20.001.30018
Adobe Acrobat Dc ≤ 20.013.20074
Adobe Acrobat Reader ≤ 17.011.30188
Adobe Acrobat Reader ≤ 20.001.300183
Adobe Acrobat Reader Dc ≤ 20.013.20074

Attack profile CVSS 3.1 · 8.8

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-21017.md and follow it. Check whether this project is affected by CVE-2021-21017. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record