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AcrobatApplication · Adobe

CVE-2021-21063

HIGH · 7.8 CVSS v3.0 Published 2021-02-11
Fix available
A fix is available. Upgrade to after 20.013.20074 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 versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by a Memory corruption vulnerability when parsing a specially crafted PDF file. 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 memory corruption vulnerability exists in Adobe Acrobat Reader DC when parsing specially crafted PDF files. The flaw allows an unauthenticated attacker to achieve arbitrary code execution in the context of the current user by tricking a victim into opening a malicious PDF document.

MitigationUpdate Adobe Acrobat Reader DC to the latest version beyond 2020.013.20074/2020.001.30018/2017.011.30188. Until patched, avoid opening PDF files from untrusted sources and consider disabling JavaScript execution in Reader settings.

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
AcrobatApplication
Affected:>= 17.011.30059, <= 17.011.30188>= 20.001.30005, <= 20.001.30018
Acrobat DcApplication
Affected:>= 15.008.20082, <= 20.013.20074
Acrobat ReaderApplication
Affected:>= 17.011.30059, <= 17.011.30188>= 20.001.30005, <= 20.001.30018
Acrobat Reader DcApplication
Affected:>= 15.008.20082, <= 20.013.20074

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:3.0/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. Identify installed Adobe product and version
    Open Adobe Acrobat Reader or Adobe Acrobat, then go to Help > About (or About Adobe Acrobat Reader). Alternatively, on Windows check the registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Acrobat\Distro\Version or on macOS check /Applications/Adobe Acrobat Reader DC.app/Contents/Info.plist
    Affected if The product is Adobe Acrobat or Adobe Acrobat Reader, or Adobe Acrobat Dc or Adobe Acrobat Reader Dc, and the version falls within 17.011.30059 through 17.011.30188, 20.001.30005 through 20.001.30018, or 15.008.20082 through 20.013.20074 (for DC variants)
  2. Confirm product variant
    Verify whether you are running the Continuous track (Dc) or the Classic track by checking the product name in Help > About or the installed folder path
    Affected if The DC (Continuous) variant is affected from version 15.008.20082 through 20.013.20074, while the Classic/Standard variant has separate ranges for versions 17.x and 20.x
  3. Assess JavaScript execution setting
    In Adobe Acrobat Reader, go to Edit > Preferences > JavaScript and verify whether 'Enable Adobe JavaScript' is checked
    Affected if JavaScript execution is enabled, as the vulnerability can be triggered through JavaScript API manipulation in malicious PDF files
  4. Review PDF handling behavior
    Check whether the system routinely opens PDF files from email attachments, web downloads, or other untrusted sources by inspecting recent file access logs or user workflow patterns
    Affected if Users routinely open PDF files from untrusted or unknown sources, as the exploit requires the victim to open a specially crafted malicious PDF document

You are affected if Adobe Acrobat Reader DC or Adobe Acrobat DC (or Classic variants) is installed with a version number matching the affected ranges and the user opens malicious 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.

From vendor data
Upgrade available Upgrade to a release after 20.013.20074
Interim mitigation

Update Adobe Acrobat Reader DC to the latest version beyond 2020.013.20074/2020.001.30018/2017.011.30188. Until patched, avoid opening PDF files from untrusted sources and consider disabling JavaScript execution in Reader settings.

Fix this in Acrobat Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
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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-2021-21063 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