Mozilla Firefox 3.0.8 and earlier 3.0.x versions allows remote attackers to cause a denial of service (memory corruption) via an XML document composed of a long series of start-tags with no corresponding end-tags. NOTE: it was later reported that 3.0.10 and earlier are also affected.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.