[tsimionescu]

It's up to you how much you trust the traffic on that machine and how you've set up access rights etc. In principle, a process with the right capabilities could snoop on the unencrypted traffic but might not be able to snoop on encrypted traffic. However, given how common local privilege escalations bugs are, if an attacker process is running on the same system, you have probably already lost (especially one that has enough privileges to capture network traffic).