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Acrobat DcApplication · Adobe

CVE-2021-35983

HIGH · 7.8 CVSS v3.1 Published 2021-08-20
Fix available
A fix is available. Upgrade to after 21.005.20054 or later.
See remediation →
81/100
Remediation priority · High
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 2021.005.20054 (and earlier), 2020.004.30005 (and earlier) and 2017.011.30197 (and earlier) are affected by an Use-after-free 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

A use-after-free vulnerability in Adobe Acrobat Reader DC allows an unauthenticated attacker to achieve arbitrary code execution in the context of the current user by tricking the victim into opening a malicious PDF file.

MitigationUpdate Adobe Acrobat Reader DC to a version later than 2021.005.20054, 2020.004.30005, or 2017.011.30197; avoid opening untrusted PDF files.

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, <= 21.005.20054>= 17.011.30059, <= 17.011.30197>= 20.001.30005, <= 20.004.30005
Acrobat Reader DcApplication
Affected:>= 15.008.20082, <= 21.005.20054>= 17.011.30059, <= 17.011.30197>= 20.001.30005, <= 20.004.30005

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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/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. Check installed Adobe Acrobat Reader DC version
    Open Adobe Acrobat Reader DC, go to Help > About Adobe Acrobat Reader DC. Alternatively, right-click the executable (AcroRd32.exe or AcroRd64.exe) in Program Files and view Properties > Details to see the Product Version.
    Affected if The version falls within any of these ranges: 15.008.20082 through 21.005.20054, 17.011.30059 through 17.011.30197, or 20.001.30005 through 20.004.30005.
  2. Confirm PDF file handling is enabled
    Verify that Adobe Acrobat Reader DC is set as the default PDF handler or that the victim can be tricked into opening a PDF file with this application. Check if PDF files open automatically in Reader when double-clicked.
    Affected if The application is configured to open PDF files and the user can be persuaded to open a malicious PDF.
  3. Verify the vulnerability trigger condition
    The vulnerability is triggered when a user opens a specially crafted malicious PDF file. This is a file-based attack vector - the attacker must deliver a malicious PDF to the victim.
    Affected if The user opens an untrusted or maliciously crafted PDF file using the affected Adobe Acrobat Reader DC version.

A user is affected if they are running Adobe Acrobat Reader DC within any of the listed version ranges AND they open a malicious PDF file, since the use-after-free flaw is triggered upon processing the malicious PDF content.

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 21.005.20054
Interim mitigation

Update Adobe Acrobat Reader DC to a version later than 2021.005.20054, 2020.004.30005, or 2017.011.30197; avoid opening untrusted PDF files.

Recommended fix Moderate confidence

Adobe Acrobat/Reader DC 2021.006.20034 or later (2021 track); 20.005.20013 or later (2020 track); 17.012.20092 or later (2017 track)

  1. 1. Identify the currently installed Adobe Acrobat or Acrobat Reader version by opening the application and navigating to Help > About Adobe Acrobat Reader (or About Adobe Acrobat).
  2. 2. Based on the installed version, determine which release track you are on (2017, 2020, or 2021).
  3. 3. For the 2017.x track (versions 17.011.30059 through 17.011.30197): Upgrade to version 17.012.20092 or later.
  4. 4. For the 2020.x track (versions 20.001.30005 through 20.004.30005): Upgrade to version 20.005.20013 or later.
  5. 5. For the 2021.x track (versions 15.008.20082 through 21.005.20054): Upgrade to version 21.006.20034 or later.
  6. 6. Download the appropriate updated version from the official Adobe website at adobe.com/downloads or your organization's software distribution point.
  7. 7. Close all Adobe applications and run the installer for the new version.
  8. 8. After installation, verify the new version by checking Help > About to confirm the patch has been applied.
Caveat Standard Adobe update; minimal risk of breaking changes in minor version upgrades; ensure compatibility with any existing PDF workflows or integrations

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
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2021-35983 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