Intel

CVE-2014-0497

Adobe Flash Player — Adobe Flash Player Integer Underflow Vulnerablity

criticalKEV: actively exploitedPoCEPSS 99.9%

Response & Mitigation

Why act now?

Prioritisation rationale

CVE-2014-0497 is an integer underflow in Adobe Flash Player enabling remote code execution with no user interaction beyond visiting a malicious page — the textbook drive-by exploitation scenario. The EPSS score of 0.9988 (100th percentile) reflects that public exploits have been embedded in exploit kits for years. CISA's addition to the KEV catalogue in September 2024 confirms that Flash components in legacy environments are still being actively targeted; typical victims include industrial control systems, kiosk terminals, and older intranet applications with Flash dependencies — all common in KRITIS sectors such as energy, water, and healthcare. Because Adobe provides no further patches, any system with an active Flash plugin must be treated as critically exposed and prioritised for immediate removal above all other remediation work.

Runbook · Step 1

Immediate response (0-24 h)

  • Remove or disable Adobe Flash Player immediately — Flash reached end-of-life on 31 December 2020; no supported patch path exists. The only effective remediation is complete removal from the environment.
  • On Windows, uninstall via "Programs and Features" and run the Adobe Flash Player Uninstaller (adobe.com/go/flashplayer_uninstall); on macOS use the Adobe-provided uninstaller; on Linux remove flash-plugin or adobe-flashplugin via the package manager.
  • Disable browser plugins: in Chrome navigate to chrome://settings/content/flash and set to "Block"; in Firefox go to about:addons → Shockwave Flash → "Never Activate"; enforce via Group Policy for IE/Edge (Computer Configuration → Administrative Templates → Windows Components → Internet Explorer → Security Zones — block ActiveX for Flash).
  • Deploy a GPO to enforce Flash blocking organisation-wide: Computer Configuration → Administrative Templates → Microsoft Edge / Internet Explorer → Turn off Adobe Flash set to "Enabled".
  • For systems where Flash cannot be removed immediately due to legacy application dependencies, network-isolate them: restrict internet access and lateral connectivity to an allowlist-only firewall ruleset.
  • Triage: review proxy logs, browser history, and EDR telemetry for Flash content fetched from external sources in the past 30 days to assess potential exposure.

Runbook · Step 2

Mitigation layers

  • Network segmentation: move Flash-dependent systems into a dedicated VLAN with no direct internet access; block outbound requests to .swf resources and known Flash CDN domains at the perimeter proxy.
  • Web proxy / content filter: block MIME types application/x-shockwave-flash and application/futuresplash, and file extensions .swf and .spl at the proxy — prevents drive-by delivery even before full uninstallation is complete.
  • IPS signature: enable a Suricata rule matching SWF magic bytes in HTTP response bodies — e.g. alert http any any -> $HOME_NET any (msg:"Blocked SWF delivery"; file.data; content:"|43 57 53|"; depth:3; sid:9000497; rev:1;) for CWS-compressed SWF; use |46 57 53| for uncompressed.
  • Application allowlisting (AppLocker / WDAC): add explicit Deny rules for Flash.ocx, NPSWF*.dll, and pepflashplayer*.dll to prevent execution even if files remain on disk.
  • Browser hardening via GPO/MDM: enforce Click-to-Play for all plugins on any system where uninstallation is still pending, preventing silent plugin execution.
  • Least privilege: ensure standard user accounts cannot install or re-enable browser plugins — revoke software installation rights where not already done.

Runbook · Step 3

Detection rules

  • Proxy / firewall logs: alert on HTTP responses with Content-Type: application/x-shockwave-flash or URLs ending in .swf from external sources — SPL: index=proxy content_type="application/x-shockwave-flash" | stats count by src_ip, url
  • EDR process tree: flag any child process spawned by FlashPlayerPlugin.exe, plugin-container.exe, or chrome.exe where the child is an unexpected executable such as cmd.exe, powershell.exe, or wscript.exe — Sysmon EID 1, filter on ParentImage containing Flash process name.
  • Windows Event Log / Sysmon EID 7: detect image loads of Flash.ocx, NPSWF32.dll, or pepflashplayer.dll by any browser process after the planned removal date — indicates incomplete uninstallation or re-installation.
  • Sigma rule (shape): title: Flash Plugin Load Post-EOL / logsource: category: image_load / detection: selection: ImageLoaded|contains: - 'Flash' - 'NPSWF' - 'pepflash' / condition: selection
  • Network telemetry (Zeek): filter files.log for mime_type == "application/x-shockwave-flash"; any hit after the removal deadline warrants immediate investigation.

Description

Integer underflow in Adobe Flash Player before 11.7.700.261 and 11.8.x through 12.0.x before 12.0.0.44 on Windows and Mac OS X, and before 11.2.202.336 on Linux, allows remote attackers to execute arbitrary code via unspecified vectors.

Source: CISA KEV CatalogCVE.org (MITRE)cvelistv5

Metrics

EPSS percentile
99.9 %
Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
Actively exploited
Show all metrics
Severity
critical
Priority score
186.40
Exploit maturity
actively exploited (KEV)
EPSS score
99.9 %
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Published
2024-09-17 00:00 UTC

Public exploit references

Public proof-of-concepts and detection templates for this vulnerability. Maturity ranges from reported PoCs through working detection scripts up to fully weaponized exploit modules. NEOSEC mirrors the code internally for forensic analysis; externally we only link to the original sources.

References & sources