Microsoft Word is prone to a remote memory-corruption vulnerability because it fails to properly allocate heap-based memory. An attacker can exploit this issue to execute arbitrary code in the context of the currently logged-in user. Failed exploit attempts will likely result in denial-of-service conditions.
Run all software as a nonprivileged user with minimal access rights.
To mitigate the impact of a successful exploit, run the affected application as a 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 suspicious or anomalous activity. This may help detect malicious actions that an attacker may take after successfully exploiting vulnerabilities in applications. Review all applicable logs regularly.
Do not accept or execute files from untrusted or unknown sources.
Never accept files from untrusted or unknown sources, because they may be malicious in nature. Avoid opening email attachments from unknown or questionable sources.
Implement multiple redundant layers of security.
Since this issue may be leveraged to execute code, we recommend memory-protection schemes, such as nonexecutable stack/heap configurations and randomly mapped memory segments. This tactic may complicate exploit attempts of memory-corruption vulnerabilities.
The vendor has released an advisory and updates. Please see the referenced advisory for details.