Browser Plug-in Vulnerabilities

Browser plug-in vulnerabilities continue to be prevalent because technologies such as ActiveX remain an easy target for security researchers and attackers alike, mostly due to fuzzer programs such as AxMan79 and COMRaider. This may indicate that there is a lack of secure development practices among ActiveX application developers. However, ActiveX is also an attractive target because many users may not be aware that they have installed vulnerable controls, and because of the relative difficulty of removing or patching ActiveX controls once they have been installed.

Symantec Internet Security Threat Report, Vol. XIII