CVE-2021-28641Network attack vector

Arbitrary code execution via use-after-free

Published Aug 20, 2021 · Updated Sep 16, 2024

Use-after-free in affected Adobe Acrobat Reader releases allows remote attackers to execute code via a malicious PDF file. Adobe has not published the affected component, freed object, or precise operation that reuses the stale allocation. A victim must open the file; the issue affects 2021.005.20054, 2020.004.30005, and 2017.011.30197 and earlier, and code runs with the current user's privileges.

CVSS severity8.8
High
EPSS probability4.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in affected Adobe Acrobat Reader releases allows remote attackers to execute code via a malicious PDF file. Adobe has not published the affected component, freed object, or precise operation that reuses the stale allocation. A victim must open the file; the issue affects 2021.005.20054, 2020.004.30005, and 2017.011.30197 and earlier, and code runs with the current user's privileges.

The record

CVE
CVE-2021-28641
Published
Aug 20, 2021
Updated
Sep 16, 2024
Vendor
Adobe
Product
Adobe Acrobat Reader
Classifications
CWE-416, T1204.002, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=2017.011.30197
  2. Affected versionversion=unspecified <=2020.004.30005
  3. Affected versionversion=unspecified <=2021.005.20054
  4. Affected versionversion=unspecified <=None

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Adobe · Adobe Acrobat Readerversion=unspecified <=2017.011.30197; version=unspecified <=2020.004.30005; version=unspecified <=2021.005.20054; version=unspecified <=None

Published CVSS scores

8.8AdobeCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1204.002Malicious File
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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