Enterprise Linux DesktopOperating system · Redhat

CVE-2016-4171

CRITICAL · 9.8 CVSS v3.1 Published 2016-06-16

Fix available

A fix is available. Upgrade to after 21.0.0.242 or later.

See remediation →

100/100

Remediation priority · Urgent

In the wild Remotely reachable No privileges Zero-click

Official description

NVD · unedited

Unspecified vulnerability in Adobe Flash Player 21.0.0.242 and earlier allows remote attackers to execute arbitrary code via unknown vectors, as exploited in the wild in June 2016.

Technical summary

dbcve analysis · moderate confidence

Critical arbitrary code execution vulnerability in Adobe Flash Player versions 21.0.0.242 and earlier. Exploited in the wild, allowing remote attackers to execute arbitrary code via unknown vectors.

MitigationImmediately update Adobe Flash Player to the latest version. Given Flash's end-of-life status and known security deficiencies, organizations should prioritize migrating away from Flash entirely rather than applying incremental patches.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Enterprise Linux DesktopOperating system

Affected:= 5.0= 6.0

Enterprise Linux ServerOperating system

Affected:= 5.0= 6.0

Enterprise Linux WorkstationOperating system

Affected:= 5.0= 6.0

Flash PlayerApplication

Affected:<= 11.2.202.621<= 21.0.0.242<= 18.0.0.352

OpensuseOperating system

Affected:= 13.1= 13.2

Linux Enterprise DesktopOperating system

Affected:= 12

Linux Enterprise Workstation ExtensionOperating system

Affected:= 12

CVSS breakdown

From the vector

Attack vector: Network
Complexity: Low
Privileges: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Identify installed Adobe Flash Player version on Windows or Mac

Open a web browser, navigate to the Adobe Flash Player version check page at about:flash (or use the official Adobe version checker at https://helpx.adobe.com/flash-player.html), or open Control Panel > Programs and Features to find the installed Flash version

Affected if The displayed version is 11.2.202.621 or earlier, 21.0.0.242 or earlier, or 18.0.0.352 or earlier
Identify Adobe Flash Player version on Linux via RPM

Run 'rpm -q flash-plugin' or 'rpm -qa | grep -i flash' in the terminal to list installed Flash packages and their versions

Affected if The reported version matches or precedes 11.2.202.621, 18.0.0.352, or 21.0.0.242
Check browser plugin status for Flash Player

Open each installed web browser (Chrome, Firefox, Internet Explorer, Edge), navigate to about:plugins or the browser's Add-ons/Extensions manager, and locate the Flash Player plugin entry

Affected if Flash Player plugin is listed as Enabled or Always Active and the version falls within the affected ranges
Verify Adobe Flash Player on Red Hat Enterprise Linux

Run 'yum list installed flash-plugin' or 'rpm -qi flash-plugin' to retrieve package information including version and install date

Affected if The package is installed and its version number is at or below 21.0.0.242, 18.0.0.352, or 11.2.202.621
Verify Adobe Flash Player on SUSE Linux distributions

Run 'rpm -qa | grep -i flash' or check via YaST software management for any installed flash-related packages and note their versions

Affected if A flash package is installed with a version matching the affected ranges for SUSE Enterprise Desktop 12 or openSUSE 13.1/13.2

A user is affected if Adobe Flash Player is installed and enabled with a version equal to or below 11.2.202.621, 18.0.0.352, or 21.0.0.242, regardless of operating system.

Generated from the published advisory. Verify against your own configuration.

Remediation

dbcve · scoped

Upgrade available Upgrade to a release after 21.0.0.242

Interim mitigation

Immediately update Adobe Flash Player to the latest version. Given Flash's end-of-life status and known security deficiencies, organizations should prioritize migrating away from Flash entirely rather than applying incremental patches.

Recommended fix High confidence

Adobe Flash Player 21.0.0.252 or later (though Flash is end-of-life; removal is strongly recommended)

1. Verify the installed Flash Player version by navigating to https://www.adobe.com/software/flash/about/ in the browser, or check the system package manager (rpm -qa | grep -i flash or dpkg -l | grep -i flash)
2. For Red Hat Enterprise Linux systems: Remove Flash Player entirely using 'yum remove flash-plugin' or 'rpm -e flash-plugin' since it is end-of-life and no longer receives security updates
3. For openSUSE systems: Remove Flash Player using 'zypper remove flash-player' or 'rpm -e flash-player'
4. Uninstall or disable all browser plugins related to Adobe Flash Player in all installed browsers (Firefox, Chrome, Chromium, etc.)
5. If Flash Player functionality is required, consider using HTML5-based alternatives or migrate to supported platforms that no longer require Flash

Caveat Adobe Flash Player reached end-of-life on December 31, 2020 and no longer receives any security updates; continuing to use it poses severe security risks

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

Fix this in Enterprise Linux Desktop Exploited in the wild — priority engagement

Consultation2.0 h
Implementation2.0 h
Testing1.0 h
Review / QA1.0 h

6.0 hours of engineering $1,090

Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.

Scan for this in your stack

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References

Primary sources

helpx.adobe.comVendor Advisory
helpx.adobe.comVendor Advisory
lists.opensuse.orgMailing ListThird Party Advisory
lists.opensuse.orgMailing ListThird Party Advisory
lists.opensuse.orgMailing ListThird Party Advisory
www.securityfocus.comThird Party AdvisoryVDB Entry
www.securitytracker.comThird Party AdvisoryVDB Entry
access.redhat.comThird Party Advisory
security.gentoo.orgThird Party Advisory
www.kb.cert.orgThird Party AdvisoryUS Government Resource
github.comIssue Tracking
www.cisa.govUS Government Resource
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-4171 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2016-4171?

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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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

At a glance

Exploited in the wildOn CISA’s known-exploited list · agencies must fix by 2022-04-15

A fix existsUpgrade to after 21.0.0.242 or later

Severity 9.8 Critical

Exploit likelihood EPSS, next 30 days 20.2%

Affects: Enterprise Linux Desktop

Remediation

Being exploited — close it fast

Fix this in Enterprise Linux Desktop 6 hrs · Moderate

Typical engagement from $1,090

Get it fixed fast See the full breakdown ↓

This CVE is on CISA’s actively-exploited list, so the clock is real — a vetted specialist can deliver a reviewed fix for your staging environment quickly.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References