Microsoft Internet Explorer is prone to a remote memory-corruption vulnerability that occurs when the application tries to parse a specially crafted web page. Successfully exploiting this issue would allow the attacker to execute arbitrary code in the context of the currently logged-in user.
Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to requests that include NOP sleds and unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.
Do not follow links provided by unknown or untrusted sources.
Web users should be cautious about following links to sites that are provided by unfamiliar or suspicious sources. Filtering HTML from emails may help remove a possible vector for transmitting malicious links to users.
Set web browser security to disable the execution of script code or active content.
Since a successful exploit of this issue requires malicious code to execute in web clients, consider disabling support for script code and active content within the client browser. Note that this mitigation tactic might adversely affect legitimate websites that rely on the execution of browser-based script code.
Implement multiple redundant layers of security.
Since attackers may be able to execute arbitrary code, implement memory-protection schemes (such as nonexecutable stack and heap configurations and randomly mapped memory segments) to reduce the chance of a successful exploit.
Microsoft has released an advisory along with fixes. Please see the references for more information.