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Acrobat DcApplication · Adobe

CVE-2021-40731

HIGH · 7.8 CVSS v3.0 Published 2021-10-15
Fix available
A fix is available. Upgrade to after 21.007.20096 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
Adobe Acrobat Reader DC version 21.007.20095 (and earlier), 21.007.20096 (and earlier), 20.004.30015 (and earlier), and 17.011.30202 (and earlier) is affected by an out-of-bounds write vulnerability when parsing a crafted JPEG2000 file, which could result in 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 an out-of-bounds write vulnerability in its JPEG2000 parsing logic. When processing a specially crafted JPEG2000 file, the application writes data beyond the boundaries of an allocated memory buffer, potentially allowing an attacker to execute arbitrary code in the context of the current user.

MitigationUpdate Adobe Acrobat Reader DC to the latest version to patch the vulnerability. Users should avoid opening untrusted PDF files, especially those containing JPEG2000 images, until updates are applied.

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, <= 21.007.20095>= 15.008.20082, <= 21.007.20096
Acrobat Reader DcApplication
Affected:>= 15.008.20082, <= 21.007.20095>= 15.008.20082, <= 21.007.20096
AcrobatApplication
Affected:>= 20.001.30005, <= 20.004.30015>= 17.011.30158, <= 17.011.30202
Acrobat ReaderApplication
Affected:>= 20.001.30005, <= 20.004.30015>= 17.011.30158, <= 17.011.30202

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. Check if Adobe Acrobat or Reader is installed
    Windows: Open Registry Editor and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Adobe or HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Adobe. Look for keys named Acrobat or Adobe Acrobat Reader. Mac: Check /Applications for Adobe Acrobat or Adobe Acrobat Reader DC.app
    Affected if No Adobe Acrobat or Adobe Acrobat Reader is found in the system, the user is not affected by this CVE.
  2. Obtain the exact version number of the installed Adobe product
    Windows: Right-click the Adobe Acrobat/Reader shortcut, select Properties, and check the Details tab for Product Version. Or open the application, go to Help > About Adobe Acrobat/Reader. Mac: Right-click the application in Applications, select Get Info, and check the Version field.
    Affected if Version cannot be determined, assume potentially affected.
  3. Compare the installed version to the affected ranges
    For Adobe Acrobat DC / Acrobat Reader DC (Continuous track): The affected version range is 15.008.20082 through 21.007.20095 or 21.007.20096. For Adobe Acrobat 2020 (Classic track): Affected range is 20.001.30005 through 20.004.30015. For Adobe Acrobat 2017 (Classic track): Affected range is 17.011.30158 through 17.011.30202. Compare your installed version number against these ranges.
    Affected if The installed version falls within any of the listed affected ranges, the system is vulnerable.
  4. Verify if the application handles PDF files with JPEG2000 images
    This is a built-in parsing capability in Adobe Acrobat and Reader. There is no user-configurable setting to disable JPEG2000 parsing. The vulnerability triggers when the application opens a PDF file containing a specially crafted JPEG2000 image.
    Affected if Adobe Acrobat or Reader is installed with an affected version number, and the application is used to open PDF files, the user is vulnerable to this flaw.

A user is affected if Adobe Acrobat or Adobe Acrobat Reader DC is installed with a version number matching the affected ranges (15.008.20082 through 21.007.20095/21.007.20096 for Continuous track, 20.001.30005 through 20.004.30015 for 2020 Classic, or 17.011.30158 through 17.011.30202 for 2017 Classic), as the JPEG2000 parsing vulnerability can be triggered when opening 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.

dbcve · scoped
Upgrade available Upgrade to a release after 21.007.20096
Interim mitigation

Update Adobe Acrobat Reader DC to the latest version to patch the vulnerability. Users should avoid opening untrusted PDF files, especially those containing JPEG2000 images, until updates are applied.

Recommended fix High confidence

Adobe Acrobat/Reader DC: 21.007.20098 or later; 2020 track: 20.004.30018 or later; 2017 track: 17.011.30205 or later

  1. 1. Open Adobe Acrobat Reader DC or Adobe Acrobat DC application
  2. 2. Navigate to Help > Check for Updates (or Help > About Adobe Acrobat Reader/Acrobat)
  3. 3. Allow the application to check for available updates
  4. 4. If updates are available, review the update details and click 'Update' or 'Install'
  5. 5. Alternatively, download the latest version from the official Adobe website: https://get.adobe.com/reader/ (for Reader) or https://get.adobe.com/acrobat/ (for Acrobat)
  6. 6. Run the installer and follow the prompts to complete the update
  7. 7. Restart the application after the update completes
  8. 8. Verify the installed version matches or exceeds the fixed release: 21.007.20098 (DC), 20.004.30018 (2020 track), or 17.011.30205 (2017 track)
Caveat Standard minor version upgrade - no expected breaking changes for end users; enterprise administrators should test in their environment before mass deployment

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
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
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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-2021-40731 in production — separate from our analysis above.

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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