ZeroHour

CVE-2014-1776

KEVmass

Use-After-Free Memory Corruption RCE in Microsoft Internet Explorer

CISA: Microsoft Internet Explorer Memory Corruption Vulnerability

CVSS
EPSS
88%p100
Published
KEV added
AI analysis

CVE-2014-1776 is a use-after-free memory corruption flaw in Microsoft Internet Explorer that can be triggered when the browser processes specially crafted web content, corrupting memory in a manner an attacker controls. A remote attacker can deliver the malicious content from a site they host or inject it into a compromised/legitimate website, causing Internet Explorer to access freed memory under attacker control. Successful exploitation allows arbitrary code execution in the context of the current user, giving the attacker that user's privileges on the client machine. Any organization or user running an affected version of Internet Explorer is exposed, and the flaw has been associated with highly targeted attack activity, including the FireEye-documented zero-day exploit in the wild and the targeted Pirpi-distributed 0-day. The vulnerability was exploited in the wild as a zero-day, was addressed by Microsoft updates, and was added to CISA's Known Exploited Vulnerabilities Catalog on 2022-01-28; no public proof-of-concept is known.

What to do: Apply Microsoft's Internet Explorer security updates per vendor instructions, prioritizing this as a KEV-required remediation, and verify all workstations still launching IE or legacy MSHTML-based content are patched. Reduce residual exposure by steering users away from Internet Explorer for untrusted sites and auditing intranet applications and tooling for lingering IE dependencies. Because the exact affected versions are not in the data, cross-check Microsoft's advisory to confirm your deployed IE versions are covered by the fix.

Affected
Microsoft Internet Explorer
Estimated exposure
mass≈ hundreds of millions of users/endpoints (IE held roughly half of global browser market share when exploited in 2014) — Estimated from Internet Explorer's dominant browser market share at the time of the 2014 zero-day activity, implying an install base in the hundreds of millions, though the precise vulnerable version range is not given in the data.

Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.

Description

Microsoft Internet Explorer contains a memory corruption vulnerability that allows remote attackers to execute code in the context of the current user.

CISA Known Exploited Vulnerability
Affected
Microsoft Internet Explorer
Required action
Apply updates per vendor instructions.
Due date
Ransomware use
Unknown
Vendors
Microsoft
Products
Internet Explorer
Weakness
CWE-416

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