CVE-2013-3918
Microsoft Windows Out-of-Bounds Write Vulnerability
Microsoft Windows
The InformationCardSigninHelper Class ActiveX control in icardie.dll in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows remote attackers to execute arbitrary code or cause a denial of service (out-of-bounds write) via a crafted web page that is accessed by Internet Explorer, as exploited in the wild in November 2013, aka "InformationCardSigninHelper Vulnerability."
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 6 October 2025. US federal agencies were required to remediate it by 27 October 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 73.7%, which is higher than 99.5% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2013-3918 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2013-3918.
What does CVE-2013-3918 affect?
CVE-2013-3918 affects Microsoft Windows. The InformationCardSigninHelper Class ActiveX control in icardie.dll in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows remote attackers to execute arbitrary code or cause a denial of service (out-of-bounds write) via a crafted web page that is accessed by Internet Explorer, as exploited in the wild in November 2013, aka "InformationCardSigninHelper Vulnerability."
How severe is CVE-2013-3918?
CVE-2013-3918 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 73.7%, higher than 99.5% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 27 October 2025.
How should organisations respond to CVE-2013-3918?
Apply the vendor patch for Microsoft Windows as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.