Actively exploited vulnerability
Microsoft Office: code execution flaw under attack
CVE-2012-1856 · Microsoft Office MSCOMCTL.OCX Remote Code Execution Vulnerability
What is affected
Microsoft Office is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.
The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption.
What an attacker can do
This is a code execution flaw. It lets an attacker run their own commands or programs on the affected system. In practice that usually means taking it over: installing malware, stealing data or using it to reach other devices on the same network.
- How it is reached
- Over the internet or network
- Access the attacker needs
- No account needed
- Does the victim have to do something?
- Yes, the victim must open or click something
What to do
- Update Microsoft Office now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
- Turn on automatic updates so the next fix arrives without you having to look for it.
- If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.
Apply updates per vendor instructions.
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on March 3, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by March 24, 2022, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 72% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99.4% of all scored vulnerabilities.
Its CVSS severity score is 8.8 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office 2003 SP3, Office 2003 Web Components SP3, Office 2007 SP2 and SP3, Office 2010 SP1, SQL Server 2000 SP4, SQL Server 2005 SP4, SQL Server 2008 SP2, SP3, R2, R2 SP1, and R2 SP2, Commerce Server 2002 SP4, Commerce Server 2007 SP2, Commerce Server 2009 Gold and R2, Host Integration Server 2004 SP1, Visual FoxPro 8.0 SP1, Visual FoxPro 9.0 SP2, and Visual Basic 6.0 Runtime allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption, aka "MSCOMCTL.OCX RCE Vulnerability."