Eudora is susceptible to a fraudulent URL vulnerability where a malicious URL can be masked behind what appears to be a legitimate link in the client. This technique is used commonly by phishers.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/33274/eudoraConceal.txt
Source: https://packetstormsecurity.com/files/33274/eudoraConceal.txt.html