Software Engineering Institute

Trend Micro describes PC-cillin as follows:

Trend Micro PC-cillin provides all-in-one antivirus security, personal firewall, and PDA protection for your PC. The user-friendly interface makes it easy to install and use. It defends your system from viruses, hackers, and other Internet security threats in email, attachments, Internet downloads, and instant messaging.
PC-cillin has the capability to scan incoming email for viruses. PC-cillin does this by running a local pop3 proxy daemon (pop3trap.exe). Trend Micro describes pop3trap.exe as follows:
Trend Micro's pop3trap.exe is an application level proxy for POP3 defined in RFC 1939. It forwards the local POP3 client requests to a remote server running on a different machine, mostly at the ISP-side. The service is only accessible from the localhost with IP address 127.0.0.1. The pop3trap.exe application runs transparent in the background and scans all mails received by POP3.
A buffer overflow in pop3trap.exe may allow a local attacker to execute arbitrary code with the privileges of the pop3 proxy.

A local attacker may be able to execute arbitrary code with the privileges of the pop3 proxy.

Apply a patch.