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Flash PlayerApplication · Adobe

CVE-2015-8421

HIGH · 10.0 CVSS v2.0 Published 2015-12-10
Fix available
A fix is available. Upgrade to after 19.0.0.241 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

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
Use-after-free vulnerability in Adobe Flash Player before 18.0.0.268 and 19.x and 20.x before 20.0.0.228 on Windows and OS X and before 11.2.202.554 on Linux, Adobe AIR before 20.0.0.204, Adobe AIR SDK before 20.0.0.204, and Adobe AIR SDK & Compiler before 20.0.0.204 allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2015-8048, CVE-2015-8049, CVE-2015-8050, CVE-2015-8055, CVE-2015-8056, CVE-2015-8057, CVE-2015-8058, CVE-2015-8059, CVE-2015-8061, CVE-2015-8062, CVE-2015-8063, CVE-2015-8064, CVE-2015-8065, CVE-2015-8066, CVE-2015-8067, CVE-2015-8068, CVE-2015-8069, CVE-2015-8070, CVE-2015-8071, CVE-2015-8401, CVE-2015-8402, CVE-2015-8403, CVE-2015-8404, CVE-2015-8405, CVE-2015-8406, CVE-2015-8410, CVE-2015-8411, CVE-2015-8412, CVE-2015-8413, CVE-2015-8414, CVE-2015-8420, CVE-2015-8422, CVE-2015-8423, CVE-2015-8424, CVE-2015-8425, CVE-2015-8426, CVE-2015-8427, CVE-2015-8428, CVE-2015-8429, CVE-2015-8430, CVE-2015-8431, CVE-2015-8432, CVE-2015-8433, CVE-2015-8434, CVE-2015-8435, CVE-2015-8436, CVE-2015-8437, CVE-2015-8441, CVE-2015-8442, CVE-2015-8447, CVE-2015-8448, CVE-2015-8449, CVE-2015-8450, CVE-2015-8452, and CVE-2015-8454.

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 Flash Player and Adobe AIR allowing arbitrary code execution. The flaw occurs when the software attempts to access memory that has already been freed, potentially enabling attackers to execute malicious code via unspecified vectors.

MitigationUpdate Adobe Flash Player to version 18.0.0.268, 19.x/20.x to 20.0.0.228 (Windows/OS X) or 11.2.202.554 (Linux), and Adobe AIR/SDK to 20.0.0.204 or later. Alternatively, disable or remove Adobe Flash Player if no longer needed.

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
Flash PlayerApplication
Affected:<= 18.0.0.261= 19.0.0.185= 19.0.0.207= 19.0.0.226= 19.0.0.245<= 11.2.202.548
AirApplication
Affected:<= 19.0.0.241
Air SdkApplication
Affected:<= 19.0.0.241
Air Sdk \& CompilerApplication
Affected:<= 19.0.0.241

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
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

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 installed Adobe Flash Player version
    On Windows, check Add/Remove Programs or the version in system registry. On macOS, check /Library/Application Support/Adobe/Flash Player or the version info in the Flash Player installer. On Linux, run 'rpm -q flash-plugin' or 'dpkg -l | grep flash'. Alternatively, visit Adobe's version check page in a browser.
    Affected if The installed version is 18.0.0.261 or lower, 19.0.0.185, 19.0.0.207, 19.0.0.226, 19.0.0.245, or 11.2.202.548 or lower.
  2. Identify installed Adobe AIR version
    On Windows, check Add/Remove Programs for 'Adobe AIR' or inspect the AIR version in the installation directory. On macOS, check /Applications/Adobe AIR or run 'system_profiler SPApplicationsDataType' to list installed applications with versions.
    Affected if The installed version is 19.0.0.241 or lower.
  3. Check for Adobe AIR SDK or AIR SDK Compiler installations
    Locate AIR SDK directories on the system. Common paths include C:\Program Files\Adobe\AIR SDK or /usr/local/air-sdk on Linux/Mac. Check the version file or the SDK version string within the SDK folder structure.
    Affected if The installed SDK version is 19.0.0.241 or lower.
  4. Verify browser plugin status for Flash Player
    In each installed browser, navigate to the plugins or extensions settings page. For Chrome, enter 'chrome://plugins' in the address bar. For Firefox, go to Add-ons > Plugins. Check if the Adobe Flash Player plugin is enabled and note its version.
    Affected if The browser Flash plugin version matches any of the affected versions listed in step 1.
  5. Check for Flash Player standalone installations
    Search for flashplayer.exe (Windows), Flash Player.app (macOS), or libflashplayer.so (Linux) in common installation directories or system search. Verify the file version property.
    Affected if The standalone player version matches any affected version listed in step 1.

A user is affected if any installed Adobe Flash Player, Adobe AIR, Adobe AIR SDK, or Adobe AIR SDK Compiler version matches the affected ranges specified for this CVE.

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 19.0.0.241
Vendor patch helpx.adobe.com →
Interim mitigation

Update Adobe Flash Player to version 18.0.0.268, 19.x/20.x to 20.0.0.228 (Windows/OS X) or 11.2.202.554 (Linux), and Adobe AIR/SDK to 20.0.0.204 or later. Alternatively, disable or remove Adobe Flash Player if no longer needed.

Recommended fix High confidence

Flash Player 20.0.0.228 (Windows/OS X) or 11.2.202.554 (Linux); AIR 20.0.0.204; AIR SDK 20.0.0.204; AIR SDK & Compiler 20.0.0.204

  1. Identify the exact Adobe Flash Player version currently installed by navigating to 'About Flash Player' in the player menu or checking the version via the system
  2. Identify the exact Adobe AIR version currently installed by checking the version in the AIR application or system settings
  3. For Flash Player: Navigate to https://get.adobe.com/flashplayer/ and download version 20.0.0.228 or later for Windows/OS X, or version 11.2.202.554 or later for Linux
  4. For Adobe AIR: Download and install Adobe AIR version 20.0.0.204 or later from the Adobe official website
  5. For Adobe AIR SDK: Download and install Adobe AIR SDK version 20.0.0.204 or later from the Adobe official developer site
  6. For Adobe AIR SDK & Compiler: Download and install Adobe AIR SDK & Compiler version 20.0.0.204 or later
  7. After installation, restart any browsers and verify the updated version numbers match the fixed releases
Caveat Flash Player is deprecated and no longer supported as of end-of-life; consider migrating away from Flash-based content entirely

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

Fix this in Flash Player Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
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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-2015-8421 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