The IE8 Developer Toolbar in Microsoft Internet Explorer 8 SP1, SP2, and SP3 allows user-assisted 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 "HTML Element Memory Corruption Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6686
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-035
http://www.us-cert.gov/cas/techalerts/TA10-159B.html