Does the innumerable places that backdoors could be hiding scare anyone else? - Compilers[1] - Networking appliance firmware - Operating systems - Security-critical software (I'm looking at YOU, OpenSSL and OpenSSH)

Something else that is rather disturbing is the fact that each and every one of those could lead to the others

Malicious software updates through network appliances and bugged compilers are the less-thought-about two of that list, and they're all the more frightening.

A few have been caught in Sendmail[2], IRC servers[3] (no big surprises there), FTPds[4], the Linux kernel[5], etc.

How many (if any) does HN think slipped through the cracks?

[1] https://en.wikipedia.org/wiki/Backdoor_%28computing%29#Reflections_on_Trusting_Trust [2] http://www.securityfocus.com/news/1113 [3] https://lwn.net/Articles/392201/ [4] http://www.iss.net/security_center/reference/vuln/FTP_ProFTPD_Backdoor.htm [5] http://www.securityfocus.com/news/7388