Microsoft Internet Explorer contains a vulnerability that could allow an unauthenticated, remote attacker to view sensitive browser-based information.
The vulnerability is due to an implementation error in Internet Explorer. An unauthenticated, remote attacker could exploit the vulnerability by convincing a user to view a malicious website. If successful, the attacker could gain access to sensitive information.
Microsoft has not confirmed this vulnerability and software updates are not available.
Indicators of Compromise
Microsoft Internet Explorer version 8.0 is vulnerable.
The vulnerability is due to an implementation error in generating event identification numbers in Internet Explorer. The mshtml.dll module generates predictable values for the IDEvent variable by using memory address pointers. As a result, memory address information may be determined by examining the IDEvent values.
An unauthenticated, remote attacker could exploit the vulnerability by convincing a user to view a malicious website. When viewed, the attacker could access sensitive information from the browser that could be used in further attacks.
To exploit the vulnerability, an attacker must convince a user to view a malicious website. The attacker may provide links to users in e-mail messages or instant messages, combined with social engineering techniques designed to make a user trust the source of a provided link.
When viewed, a malicious website could allow the attacker to view browser-based information that could assist the attacker in further exploits. The information gained could allow the attacker to determine memory addresses to bypass protections such as address space layout randomization (ASLR) or other memory protections. The information could also be used to determine the uniqueness of a user's browser contributing to a browser or system fingerprint, allowing the attacker to track user browsing habits.
Administrators are advised to apply software updates as they become available.
Users are advised not to open e-mail messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in e-mail messages are safe, they are advised not to open them.
Administrators are advised to monitor critical systems.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.