A buffer overflow vulnerability in Eudora, the popular email client, creates a mechanism for crackers to compromise targeted PCs. The problem stems from a failure to properly verify the "From:" and "Reply-To:" when users of vulnerable versions of Eudora select "Reply-To-All". This shortcoming creates a means for hackers to spam users with a maliciously constructed email designed to trigger this buffer overflow condition. The vulnerability was discovered in Eudora version 5.x by Japanese security researcher Hisayuki Shinmachi of Secure Net Services in January and announced yesterday. Users are advised to update to Eudora 5.1-Jr3 (Japanese) or Eudora 6.0 (English) in order to shore up their security defences, as explained in an advisory by Secunia here. Although Eudora security problems are not unprecedented, the package is far less afflicted with security issues than Microsoft"s email client, known in these parts as Lookout.