“This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Internet Explorer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of CMarkup objects. The allocation initially happens within CMarkup::CreateInitialMarkup. The free happens after the execution of certain JavaScript code followed by a CollectGarbage call. By manipulating a document’s elements an attacker can force a dangling pointer to be reused after it has been freed. An attacker can leverage this vulnerability to execute code under the context of the current process.” reports ZDI.

“In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically by getting them to click a link in an email message or in an Instant Messenger message that takes users to the attacker’s website, or by getting them to open an attachment sent through email,” reads the ZDI post. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights” stated ZDI.

Pierluigi Paganini

(Security Affairs –  Internet Explorer 8, Zero-day)