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Acrobat DcApplication · Adobe

CVE-2021-28561

HIGH · 8.8 CVSS v3.1 Published 2021-09-02
Fix available
A fix is available. Upgrade to after 21.001.20150 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by a memory corruption 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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a memory corruption vulnerability in Adobe Acrobat Reader DC that allows an unauthenticated attacker to achieve arbitrary code execution in the context of the current user. Exploitation requires user interaction—the victim must open a malicious PDF file. Affected versions include 2021.001.20150 and earlier, 2020.001.30020 and earlier, and 2017.011.30194 and earlier.

MitigationUpdate Adobe Acrobat Reader DC to a patched version newer than the affected releases. Until updated, users should avoid opening untrusted PDF files from unknown sources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Acrobat DcApplication
Affected:>= 15.008.20082, <= 21.001.20150
Acrobat Reader DcApplication
Affected:>= 15.008.20082, <= 21.001.20150
AcrobatApplication
Affected:>= 17.011.30059, <= 17.011.30194>= 20.001.30005, <= 20.001.30020
Acrobat ReaderApplication
Affected:>= 17.011.30059, <= 17.011.30194>= 20.001.30005, <= 20.001.30020

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

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

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Adobe Acrobat or Reader is installed
    On Windows, check the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Adobe or look in C:\Program Files\Adobe\ for Acrobat or Reader folders. On macOS, check /Applications for Adobe Acrobat or Adobe Reader.
    Affected if Adobe Acrobat or Adobe Reader software is present on the system
  2. Identify the installed product version
    Open Adobe Acrobat/Reader, then go to Help > About Adobe Acrobat Reader (or About Adobe Acrobat). Alternatively, right-click the executable in Program Files and select Properties > Details to view the File Version.
    Affected if The version displayed cannot be determined or is unknown
  3. Compare version against affected ranges
    Check if the installed version falls within any of these ranges: 15.008.20082 to 21.001.20150 (2021.x track), 20.001.30005 to 20.001.30020 (2020.x track), 17.011.30059 to 17.011.30194 (2017.x track), or any version 2017.011.30194 or earlier.
    Affected if The installed version matches one of the affected version ranges listed
  4. Verify the product handles PDF files
    Check if the Adobe product is configured as the default PDF handler or has been used recently to open PDF files. Look for PDF file associations in the system or recent PDF files opened by the application.
    Affected if The product processes or displays PDF documents and could be triggered to parse a malicious file

A user is affected if Adobe Acrobat or Adobe Reader is installed with a version number within the affected ranges (15.008.20082 through 21.001.20150, 20.001.30005 through 20.001.30020, or 17.011.30059 through 17.011.30194) and the application handles PDF files.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 21.001.20150
Interim mitigation

Update Adobe Acrobat Reader DC to a patched version newer than the affected releases. Until updated, users should avoid opening untrusted PDF files from unknown sources.

Recommended fix High confidence

Acrobat DC 2021: upgrade to 21.001.20154 or later; Acrobat DC 2020: upgrade to 20.001.30025 or later; Acrobat 2017: upgrade to 17.011.30210 or later

  1. 1. Close all instances of Adobe Acrobat or Adobe Acrobat Reader DC
  2. 2. Visit the Adobe Acrobat download page at https://get.adobe.com/reader/ or your organization's software distribution channel
  3. 3. For Acrobat Reader DC 2021: Download and install version 21.001.20154 or later
  4. 4. For Acrobat Reader DC 2020: Download and install version 20.001.30025 or later
  5. 5. For Acrobat Reader 2017: Download and install version 17.011.30210 or later
  6. 6. For Acrobat DC 2021: Download and install version 21.001.20154 or later
  7. 7. For Acrobat 2020: Download and install version 20.001.30025 or later
  8. 8. For Acrobat 2017: Download and install version 17.011.30210 or later
Caveat Minor - this is a security patch release; ensure compatibility with existing PDF workflows and any third-party plugins before deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Acrobat Dc Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-28561 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data