CVE-2021-28640
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 · uneditedAcrobat 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 authenticated 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 confidenceUse-after-free vulnerability in Adobe Acrobat Reader DC affecting versions 2021.005.20054 and earlier, 2020.004.30005 and earlier, and 2017.011.30197 and earlier. An authenticated attacker can achieve arbitrary code execution in the context of the current user by enticing a victim to open a malicious PDF file.
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>= 15.008.20082, <= 21.005.20054>= 17.011.30059, <= 17.011.30197>= 20.001.30005, <= 20.004.30005>= 15.008.20082, <= 21.005.20054>= 17.011.30059, <= 17.011.30197>= 20.001.30005, <= 20.004.30005CVSS 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
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Verify Adobe Acrobat installationCheck for installed Adobe Acrobat or Adobe Acrobat Reader DC on the system. On Windows, open Programs and Features or check the installation directory (typically C:\Program Files\Adobe\Acrobat DC or C:\Program Files (x86)\Adobe\Acrobat Reader DC). On macOS, check /Applications for Adobe Acrobat or Adobe Acrobat Reader.Affected if Adobe Acrobat DC or Adobe Acrobat Reader DC is installed
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Determine installed versionLocate the executable (Acrobat.exe or AcroRd32.exe) and view its properties, or open the application and go to Help > About Adobe Acrobat Reader DC. On Windows, you can also query the registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Acrobat Reader\DC\InstallPath or use command: wmic product where "name like 'Adobe Acrobat%'" get versionAffected if Unable to determine version or version falls within affected ranges
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Compare version against affected rangesIf version is identified, compare it to the affected ranges: 15.008.20082 to 21.005.20054, 17.011.30059 to 17.011.30197, or 20.001.30005 to 20.004.30005Affected if Installed version matches any of the three affected ranges (inclusive)
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Assess exposure to malicious PDFsDetermine if the user or organization routinely opens PDF files from untrusted sources, as exploitation requires the victim to open a specially crafted malicious PDF fileAffected if Users open PDF files from untrusted or unknown sources without prior scanning
A system is affected if Adobe Acrobat DC or Adobe Acrobat Reader DC is installed with a version matching one of the three vulnerable ranges (15.008.20082-21.005.20054, 17.011.30059-17.011.30197, or 20.001.30005-20.004.30005) and the user opens untrusted PDF files.
Generated from the published advisory. Verify against your own configuration.
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 dataUpdate Adobe Acrobat Reader DC to a patched version beyond the affected releases. Users should not open untrusted PDF files and organizations should deploy patches via enterprise patch management tools.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-28640 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-28640 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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