The loginDefaultEncrypt algorithm in loginLib in Wind River VxWorks before 6.9 does not properly support a large set of distinct possible passwords, which makes it easier for remote attackers to obtain access via a (1) telnet, (2) rlogin, or (3) FTP session.
https://support.windriver.com/olsPortal/faces/maintenance/downloadDetails.jspx?contentId=033709
http://www.kb.cert.org/vuls/id/MAPG-863QH9
http://www.kb.cert.org/vuls/id/840249
http://blog.metasploit.com/2010/08/vxworks-vulnerabilities.html