dbcve.org
AcrobatApplication · Adobe

CVE-2021-21035

HIGH · 8.8 CVSS v3.1 Published 2021-02-11
Fix available
A fix is available. Upgrade to after 20.013.20074 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 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by a 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

Use After Free vulnerability in Adobe Acrobat Reader DC that allows an unauthenticated attacker to achieve arbitrary code execution through a maliciously crafted PDF file opened by the victim.

MitigationUpdate Adobe Acrobat Reader DC to a patched version beyond 2020.013.20074/2020.001.30018/2017.011.30188; avoid opening untrusted PDF files until patched.

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:>= 17.0, <= 17.011.30188>= 20.0, <= 20.001.30018
Acrobat DcApplication
Affected:<= 20.013.20074
Acrobat ReaderApplication
Affected:>= 17.0, <= 17.011.30188>= 20.0, <= 20.001.300183
Acrobat Reader DcApplication
Affected:<= 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
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. Check if Adobe Acrobat Reader DC is installed
    On Windows, open Registry Editor and navigate to HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\AcroRd32.exe, or check C:\Program Files\Adobe\Acrobat Reader DC\ for the AcroRd32.exe file. On macOS, check /Applications/ for Adobe Acrobat Reader DC.app.
    Affected if The product is not installed or only modern versions beyond the affected ranges are present.
  2. Retrieve the installed version number
    On Windows, right-click AcroRd32.exe in the Adobe Acrobat Reader DC installation folder, select Properties, and view the Details tab for the Product Version. Alternatively, run 'AcroRd32.exe /v' from the command line in that folder.
    Affected if A version number is returned that falls within the affected ranges: 17.0 through 17.011.30188, 20.0 through 20.001.30018/20.001.300183, or any version up to 20.013.20074 for DC variants.
  3. Compare against affected version ranges
    Match your installed version against all affected ranges: 17.x versions up to 17.011.30188, 20.x versions up to 20.001.30018 (Reader) or 20.001.300183 (Acrobat), and DC versions up to 20.013.20074.
    Affected if The installed version matches any of these ranges, indicating the installation is vulnerable to this Use After Free flaw.
  4. Confirm the vulnerability trigger condition
    Verify that PDF files can be opened in the installed Adobe Acrobat Reader DC version. The flaw is triggered when a victim opens a maliciously crafted PDF file.
    Affected if The affected version is installed AND the application can open PDF files, making arbitrary code execution via malicious PDF possible.

A user is affected if Adobe Acrobat Reader DC (or Acrobat) is installed with a version falling within 17.0-17.011.30188, 20.0-20.001.30018/20.001.300183, or up to 20.013.20074 for DC variants.

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 a patched version beyond 2020.013.20074/2020.001.30018/2017.011.30188; avoid opening untrusted PDF files until patched.

Fix this in Acrobat Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-21035 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-21035 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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