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AcrobatApplication · Adobe

CVE-2021-21088

HIGH · 7.8 CVSS v3.1 Published 2023-09-06
Fix available
A fix is available. Upgrade to 17.011.30190 / 20.001.30020 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 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

Adobe Acrobat Reader DC contains a Use After Free vulnerability where the software attempts to use memory that has already been freed, allowing an unauthenticated attacker to achieve arbitrary code execution through a malicious PDF file opened by the victim.

MitigationUpdate Adobe Acrobat Reader DC to the latest patched version. Avoid opening untrusted or unexpected PDF files from unverified 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
AcrobatApplication
Affected:>= 17.011.30180, < 17.011.30190>= 20.001.30005, < 20.001.30020
Acrobat DcApplication
Affected:>= 15.007.20033, < 21.001.20135
Acrobat ReaderApplication
Affected:>= 17.011.30180, < 17.011.30190>= 20.001.30005, < 20.001.30020
Acrobat Reader DcApplication
Affected:>= 15.007.20033, < 21.001.20135

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. Identify the installed Adobe product
    Open Adobe Acrobat Reader or Adobe Acrobat, then go to Help > About Adobe Acrobat Reader (or Adobe Acrobat). Alternatively, check Add/Remove Programs (Windows) or Applications folder (Mac) for the installed version.
    Affected if Adobe Acrobat or Adobe Acrobat Reader is installed on the system
  2. Determine the exact version number
    Note the full version number displayed in the About dialog or installer information. Look for a number in the format such as 17.011.30180, 20.001.30005, or 15.007.20033.
    Affected if A version number is found that matches the affected ranges
  3. Compare version against affected ranges
    Check if the installed version falls within any of these ranges: 17.011.30180 through 17.011.30189, 20.001.30005 through 20.001.30019 (for standard Acrobat/Reader), or 15.007.20033 through 21.001.20134 (for DC variants).
    Affected if The installed version is greater than or equal to the lower bound AND less than the upper bound of any affected range listed

If Adobe Acrobat or Adobe Acrobat Reader is installed and the version falls within any of the affected ranges, the environment is vulnerable when processing untrusted 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 17.011.30190 / 20.001.30020 / 21.001.20135 or later
Fixed in 17.011.3019020.001.3002021.001.20135
Interim mitigation

Update Adobe Acrobat Reader DC to the latest patched version. Avoid opening untrusted or unexpected PDF files from unverified sources.

Recommended fix High confidence

Adobe Acrobat/Reader DC version 21.001.20135 or later (DC track); Adobe Acrobat/Reader version 20.001.30020 or later (2020 track); Adobe Acrobat/Reader version 17.011.30190 or later (2017 track)

  1. 1. Determine which Adobe Acrobat or Reader product line and version is currently installed (Acrobat, Acrobat DC, Acrobat Reader, or Acrobat Reader DC)
  2. 2. For Acrobat/Acrobat Reader versions 17.x (2017 track): upgrade to version 17.011.30190 or later
  3. 3. For Acrobat/Acrobat Reader versions 20.x (2020 track): upgrade to version 20.001.30020 or later
  4. 4. For Acrobat DC/Acrobat Reader DC versions 15.x through 20.x: upgrade to version 21.001.20135 or later
  5. 5. Verify the installation by checking Help > About Adobe Acrobat/Reader to confirm the updated version number
  6. 6. Ensure users are advised not to open untrusted or unexpected PDF files from unknown sources
Caveat Standard Adobe update considerations: verify compatibility with existing PDF workflows and plugins; enterprise deployments should test in controlled environment before broad rollout

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

Fix this in Acrobat 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
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2021-21088 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