CVE-2021-28634Public exploit

Code execution via unquoted AcrobatUtils file path

Published Aug 20, 2021 · Updated Sep 16, 2024

OS command injection in Adobe Acrobat Reader allows local users to execute code when a victim opens a malicious Microsoft Office file. The OpenPDFFile and ConvertToPDF handlers in AcrobatUtils.scpt pass a caller-controlled path directly to do shell script without shell quoting, enabling current-user commands outside the Office sandbox. Reader DC 2021.005.20054 and earlier, Reader 2020 2020.004.30005 and earlier, and Reader 2017 2017.011.30197 and earlier are affected; exploitation requires an authenticated local attacker and victim interaction.

CVSS severity8.2
High
EPSS probability2.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Adobe Acrobat Reader allows local users to execute code when a victim opens a malicious Microsoft Office file. The OpenPDFFile and ConvertToPDF handlers in AcrobatUtils.scpt pass a caller-controlled path directly to do shell script without shell quoting, enabling current-user commands outside the Office sandbox. Reader DC 2021.005.20054 and earlier, Reader 2020 2020.004.30005 and earlier, and Reader 2017 2017.011.30197 and earlier are affected; exploitation requires an authenticated local attacker and victim interaction.

The record

CVE
CVE-2021-28634
Published
Aug 20, 2021
Updated
Sep 16, 2024
Vendor
Adobe
Product
Adobe Acrobat Reader
Classifications
CWE-78, T1204.002, T1059.002
Attack vector
local
Privileges
authenticated

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

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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 vectorlocal
Required privilegesauthenticated

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

8.5NIST NVDAV:N/AC:M/Au:S/C:C/I:C/A:C
8.2AdobeCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1204.002Malicious File
T1059.002AppleScript

Public exploit references

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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