Internet Explorer 6.0 SP1 and earlier, and possibly other versions, allows remote attackers to cause a denial of service (application crash from "memory corruption") via certain malformed Cascading Style Sheet (CSS) elements that trigger heap-based buffer overflows, as demonstrated using the "<STYLE>@;/*" string, possibly due to a missing comment terminator that may cause an invalid length to trigger a large memory copy operation, aka the "CSS Heap Memory Corruption Vulnerability."