Microsoft Internet Explorer 6, 6 SP1, 7, and 8 does not properly handle objects in memory, which allows remote attackers to execute arbitrary code by accessing an object that (1) was not properly initialized or (2) is deleted, leading to memory corruption, aka "Uninitialized Memory Corruption Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8302
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-018
http://www.vupen.com/english/advisories/2010/0744
http://www.us-cert.gov/cas/techalerts/TA10-089A.html
http://www.us-cert.gov/cas/techalerts/TA10-068A.html