CVE-2012-0767: Adobe Flash Player Cross-Site Scripting (XSS) Vulnerability

CVE-2012-0767 is a cross-site scripting (XSS) vulnerability in Adobe Flash Player. It allows a remote attacker to inject web script or HTML into content handled by the player. Because Flash once ran widely in browsers and embedded applications, unpatched or leftover installations can still expose users and internal systems to script injection that steals session data, alters pages, or delivers further payloads. The product is end-of-life; CISA advises disconnecting it if it remains in use.

How it works

The weakness is CWE-79: improper neutralization of input during web page generation. In this class of flaw, attacker-controlled data is reflected or stored without adequate encoding or validation, so a browser or plugin executes it as script or markup. For Adobe Flash Player, a remote attacker can supply crafted content that the player processes in a way that injects web script or HTML. The injected code then runs in the security context of the affected page or application. Exact trigger conditions and input vectors are not detailed here; confirm mechanics against the vendor advisory. No public facts in this record describe ransomware use of this CVE.

Am I affected? How to find it in your systems

Adobe Flash Player historically appeared as a browser plugin, ActiveX control, or standalone runtime on Windows, macOS, and other desktops, and sometimes inside enterprise kiosks, training tools, or legacy line-of-business apps. Inventory every endpoint and server that might still host the Flash runtime or SWF-handling components.

• Search installed programs, browser plugin lists, and package inventories for any Adobe Flash Player or related runtime entries.
• Scan file systems for Flash libraries, projector binaries, and .swf files that may be loaded by custom applications.
• Check software bill-of-materials and vulnerability scanners for residual Flash references; treat any detection as in-scope because the product is end-of-life.
• Review web proxy, browser, and endpoint logs for attempts to load Flash content or for unexpected script execution following Flash-related requests. Specific exploitation telemetry is not provided in the given facts, so baseline normal Flash activity (if any remains) and alert on anomalies.

Confirm exact affected builds and configurations solely against the original vendor advisory; do not rely on version guesses.

How to remediate

The primary remediation is removal. CISA states the impacted product is end-of-life and should be disconnected if still in use. Uninstall Adobe Flash Player completely from every system, revoke any Group Policy or configuration that re-enables it, and block the loading of Flash content at the browser and network layers. Where a vendor security update was once issued for this CVE, apply that update only as an interim step on systems that cannot yet be decommissioned, then proceed to full removal. After uninstall, verify that no Flash libraries or plugins remain and that browsers no longer offer Flash rendering.

For the broader XSS class, ensure any remaining web applications that once relied on Flash now encode output, apply content-security policies, and avoid reflecting untrusted input. Re-scan after changes to confirm the runtime is gone.

If you can't patch immediately

If immediate uninstall is blocked by a legacy dependency, isolate and harden until removal is possible:

• Segment affected hosts onto restricted network zones with no unnecessary internet or lateral access.
• Disable the Flash plugin or ActiveX control via browser and OS policy so it cannot load.
• Use application allow-listing to prevent execution of Flash binaries and related helpers.
• Apply virtual patching or WAF rules that block known Flash content types and suspicious script patterns in transit; tune rules to your environment and validate against the vendor advisory.
• Increase monitoring on those hosts for process creation, unexpected network connections, and script injection indicators, and retain logs for incident review.

These steps only reduce risk; they do not replace disconnection of the end-of-life product.

If your data may have been exposed

Actively exploited vulnerabilities can lead to session theft, account compromise, or broader breaches. If Flash Player was present and reachable, treat the possibility of script injection seriously: rotate credentials that may have been exposed in the browser context, review access logs, and check for unauthorized changes. You can run a free exposure scan of your email addresses against known breach data to see whether associated accounts appear in public breach corpora and then take appropriate follow-up steps.