Two Microsoft security updates for Internet Explorer can break the functionality of Web sites that use certain custom applications.
The problems occur after installing the patches Microsoft delivered with security bulletins MS05-038 and MS05-052, Microsoft said in two advisories posted on its Web site Wednesday. The bulletins were issued in August and October, respectively.
Both patches can cause problems with ActiveX controls, small programs designed to perform simple tasks that can make a Web site more interactive. The MS05-038 patch can also hinder Java applications. After the patches are installed, applications that are programmed in specific ways will no longer work in Internet Explorer, Microsoft said.
To resolve this issue, Microsoft advises developers to recompile an affected ActiveX control and mark it as safe when run in an Internet browser, according to the advisory. As a workaround, users of sites with ActiveX controls that no longer work can lower their IE security settings, the company said, although it does not recommend doing so.