Microsoft Windows contains a buffer overflow in the Compressed (zipped) Folders feature. A maliciously crafted compressed file could overrun an internal buffer causing arbitrary code to be executed in the security context of the current user.
Run all software as a nonprivileged user with minimal access rights.
All client software should be run with the least amount of privileges required. This will help limit the consequences of successful exploitation of this and other latent vulnerabilities.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy network intrusion detection systems to monitor all network traffic for signs of suspicious or anomalous activity. This may aid in detecting attempts to exploit latent vulnerabilities or in detecting malicious activity that occurs as a result of successful exploitation.
Do not accept or execute files from untrusted or unknown sources.
In order for this vulnerability to be exploited, a user would have to open a compressed file. Only open files from known and trusted sources after verifying their integrity.
Do not accept communications that originate from unknown or untrusted sources.
Disabling client support for HTML email may limit exposure to this attack vector.
Microsoft has released a bulletin that includes fixes to address this issue for supported versions of the operating system. RealNetworks has released a security advisory outlining a buffer overflow vulnerability in skin file processing due to this issue. The advisory also outlines affected packages and solutions. Please see the referenced advisory for more information and contact the vendor for upgrade availability.