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Acrobat DcApplication · Adobe

CVE-2021-28558

HIGH · 8.8 CVSS v3.0 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 an Heap-based buffer overflow vulnerability in the PDFLibTool component. 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

Heap-based buffer overflow vulnerability in Adobe Acrobat Reader DC's PDFLibTool component allows an unauthenticated attacker to achieve arbitrary code execution through a malicious PDF file opened by the victim.

MitigationUpdate Adobe Acrobat Reader DC to a version newer than 2021.001.20150, 2020.001.30020, or 2017.011.30194 (depending on the track in use).

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:3.0/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. Identify if Adobe Acrobat/Reader DC (2021 track) is installed
    Look for Adobe Acrobat DC or Adobe Acrobat Reader DC in the system's installed programs list, or check the product information within the application Help > About menu
    Affected if The product is installed and the version number falls between 15.008.20082 and 21.001.20150 inclusive
  2. Determine the installed version of Acrobat/Reader DC (2021 track)
    Open the application, go to Help > About Adobe Acrobat/Reader DC, or view the version in the Windows Programs and Features list
    Affected if The displayed version is greater than or equal to 15.008.20082 AND less than or equal to 21.001.20150
  3. Identify if Adobe Acrobat or Acrobat Reader (2017 track) is installed
    Look for Adobe Acrobat 2017 or Adobe Acrobat Reader 2017 in installed programs, or check the application's About dialog
    Affected if The product is installed and the version is between 17.011.30059 and 17.011.30194 inclusive
  4. Identify if Adobe Acrobat or Acrobat Reader (2020 track) is installed
    Look for Adobe Acrobat 2020 or Adobe Acrobat Reader 2020 in installed programs, or check the application's About dialog
    Affected if The product is installed and the version is between 20.001.30005 and 20.001.30020 inclusive

You are affected if any Adobe Acrobat or Adobe Acrobat Reader version installed on the system falls within any of the affected ranges: 15.008.20082-21.001.20150, 17.011.30059-17.011.30194, or 20.001.30005-20.001.30020.

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 version newer than 2021.001.20150, 2020.001.30020, or 2017.011.30194 (depending on the track in use).

Recommended fix High confidence

Upgrade to Adobe Acrobat Reader DC / Acrobat DC 2021.001.20154+ (or 2020.001.30025+ for 2020 track, or 2017.011.30210+ for 2017 track), or migrate to the latest continuous release

  1. 1. Identify the current Adobe Acrobat or Adobe Acrobat Reader DC version by navigating to Help > About Adobe Acrobat Reader DC (or About Adobe Acrobat).
  2. 2. Determine which track your installation belongs to: 2021 (21.xxx), 2020 (20.xxx), or 2017 (17.xxx) based on the version number.
  3. 3. For the 2021 track: Download and install version 2021.001.20154 or later from the Adobe Acrobat download page.
  4. 4. For the 2020 track: Download and install version 2020.001.30025 or later from the Adobe Acrobat download page.
  5. 5. For the 2017 track: Download and install version 2017.011.30210 or later from the Adobe Acrobat download page.
  6. 6. Alternatively, enable automatic updates: Go to Edit > Preferences > Updater and select 'Automatically install updates'.
  7. 7. After installation, restart the application and verify the version has been updated to a fixed release.
  8. 8. Educate users to avoid opening untrusted PDF files from unknown sources, as exploitation requires user interaction.
Caveat Standard Adobe update; ensure compatibility with any existing PDF workflows or plugins before deploying enterprise-wide

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

Fix this in Acrobat Dc Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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Scan for this in your stack

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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-2021-28558 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