CVE-2016-4171 — Flash Player
CRITICALCVE-2016-4171 is a critical-severity (CVSS 9.8) remote code execution vulnerability in adobe flash player. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-25) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
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.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-03-25. Federal agencies were required to remediate by 2022-04-15.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2016-4171.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2016-4171 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 395,249 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Description
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.
Affected Products
flash playeradobeopensuseopensuseenterprise linux desktopredhatenterprise linux serverredhatenterprise linux workstationredhatlinux enterprise desktopsuseResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every adobe flash player deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2016-4171 yet — track the adobe flash player advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 5 Supplementary | flash-plugin-0:11.2.202.626-1.el5_11 | RHSA-2016:1238 |
Frequently Asked Questions
Is CVE-2016-4171 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.