Media EncoderApplication · Adobe

CVE-2021-42721

HIGH · 7.8 CVSS v3.1 Published 2021-11-16
Fix available
A fix is available. Upgrade to after 15.4 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 Bridge versions 11.1.1 and earlier are affected by a use-after-free vulnerability in the processing of Format event actions that 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 Bridge versions 11.1.1 and earlier contain a use-after-free vulnerability in the processing of Format event actions. When a user opens a malicious PDF file containing specially crafted Format event actions, the vulnerability allows an attacker to execute arbitrary code in the context of the current user's privileges.

MitigationApply the vendor security update for Adobe Acrobat Bridge to version 11.1.2 or later. Until patched, warn users against opening untrusted PDF files and consider deploying additional document sandboxing controls.

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
Media EncoderApplication
Affected:<= 15.4

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. Verify Adobe Acrobat Bridge installation
    Check for Bridge in the Windows registry at HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\Acrobat Bridge 11.exe, or look for the executable in typical install paths like C:\Program Files\Adobe\Adobe Bridge 11\ or C:\Program Files (x86)\Adobe\Adobe Bridge 11\
    Affected if Adobe Acrobat Bridge version 11.1.1 or earlier is installed
  2. Determine installed Bridge version
    Right-click on the Bridge executable (Bridge.exe), select Properties, and check the File Version on the Details tab. Alternatively, run 'Bridge.exe -version' from the install directory if supported.
    Affected if The reported version is 11.1.1, 11.1.0, or any earlier 11.x release (versions prior to 11.1.2)
  3. Confirm Format event action processing is accessible
    Adobe Acrobat Bridge processes PDF files including their event actions when opening them for preview or editing. Verify Bridge can open PDF documents by attempting to open a PDF file through Bridge's File > Open menu.
    Affected if Bridge can open PDF files and process their event actions, meaning the vulnerability is reachable if a malicious PDF is opened
  4. Check for recent Bridge usage or logs
    Review Bridge application logs in the user profile directory (typically %APPDATA%\Adobe\Bridge\Logs\) for any suspicious PDF open events, or check browser/download folders for recently opened PDF files that may have been processed through Bridge.
    Affected if Evidence exists of untrusted PDF files having been opened through Bridge, indicating potential exploitation attempt

You are affected if Adobe Acrobat Bridge version 11.1.1 or earlier is installed and users can open PDF files through it, allowing specially crafted Format event actions to trigger the use-after-free condition.

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 15.4
Interim mitigation

Apply the vendor security update for Adobe Acrobat Bridge to version 11.1.2 or later. Until patched, warn users against opening untrusted PDF files and consider deploying additional document sandboxing controls.

Fix this in Media Encoder Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2021-42721 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