CVE-2021-28636

Code execution via uncontrolled search path

Published Aug 20, 2021 · Updated Sep 16, 2024

Uncontrolled search path handling in Adobe Acrobat Reader allows local users to execute code when a victim opens a malicious file. Adobe has not disclosed the executable-loading locus or exact resource search operation; exploitation requires content in the victim's C: root. Affected releases are 2021.005.20054, 2020.004.30005, and 2017.011.30197 and earlier, with execution limited to the current user.

CVSS severity7.3
High
EPSS probability2.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled search path handling in Adobe Acrobat Reader allows local users to execute code when a victim opens a malicious file. Adobe has not disclosed the executable-loading locus or exact resource search operation; exploitation requires content in the victim's C: root. Affected releases are 2021.005.20054, 2020.004.30005, and 2017.011.30197 and earlier, with execution limited to the current user.

The record

CVE
CVE-2021-28636
Published
Aug 20, 2021
Updated
Sep 16, 2024
Vendor
Adobe
Product
Adobe Acrobat Reader
Classifications
CWE-427, CAPEC-471, T1204.002
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

7.3Adobe Systems IncorporatedCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
8.5NIST NVDAV:N/AC:M/Au:S/C:C/I:C/A:C

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
CAPEC-471Search Order Hijacking
T1204.002Malicious File

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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