Microsoft Windows InformationCardSigninHelper Out-of-Bounds Write (CVE-2013-3918)

Historical catalog analysis: CISA added this entry on October 06, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2013-3918 is an out-of-bounds write vulnerability located within the InformationCardSigninHelper Class ActiveX control (icardie.dll) in Microsoft Windows. This flaw allows for remote code execution (RCE) if a user views a specially crafted webpage designed to trigger the vulnerability. Upon successful exploitation, the attacker operates with the same privileges as the current user.

Exposure and applicability

The attack vector is network-based, requiring user interaction via a web browser. This vulnerability is particularly relevant for organizations maintaining legacy infrastructure, as the affected product may be end-of-life (EoL) or end-of-service (EoS). The risk is highest in environments where outdated Windows versions are still active and capable of executing ActiveX controls.

Remediation priorities

Our analysis suggests prioritizing remediation based on the lifecycle status of the affected assets:

1. Decommissioning EoL/EoS Systems: For systems that have reached end-of-life or end-of-service, our primary recommendation is to discontinue product utilization entirely, as these systems may no longer receive security updates.
2. Patch Deployment: For supported versions of Windows, administrators should apply the vendor-provided mitigations and security updates associated with this vulnerability.
3. Attack Surface Reduction: In environments where immediate patching or decommissioning is not feasible, reducing the ability of users to execute ActiveX controls via web browsers could reduce the likelihood of initial compromise.

How to validate remediation

Verification must move beyond simple version checks to ensure the exposure is actually reduced:

• Component Audit: Confirm whether icardie.dll is present and registered on the system. The removal or updating of this specific DLL is a prerequisite for mitigation.
• Configuration Validation: If ActiveX controls have been disabled as a compensating control, verify through group policy or browser configuration that the InformationCardSigninHelper class cannot be instantiated by a web page.
• Patch Verification: Confirm the installation of the specific vendor security update identified in the remediation guidance.

Limits and open questions

A significant residual risk remains for organizations using EoL/EoS software where official patches may be unavailable or unsupported. While applying updates reduces exposure, it does not eliminate all risks associated with legacy ActiveX components. It remains unknown whether this vulnerability is currently being leveraged in active ransomware campaigns.

Source and editorial note

CVE-2013-3918: Microsoft Windows Out-of-Bounds Write Vulnerability · Source date: October 06, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: October 09, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 01, 2026 at 00:20 UTC.

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