Microsoft Exchange Server is prone to a remote code-execution vulnerability. Remote attackers may exploit this issue by sending maliciously constructed TNEF-encoded email data to vulnerable servers. This issue will be triggered when a user views or previews the malicious email. Successfully exploiting this issue would allow the attacker to execute arbitrary code on an affected computer in the context of the affected application.
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.
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 along with fixes to address this issue. Please see the references for more information.