Courtesy of Don Kaminsky's slides for his Black Hat DNS talk, I wound up reading Attacks on PackageManagers ,which identifies a number of attacks that can be mounted if you canset yourself up as a package repository mirror for your favoriteLinux distribution. A number of the attacks are straightforward,but judging from the Slashdot discussion the dangers of unsignedrepository metadata are not as clear. So here is an attempt toexplain them simply.

Suppose that you are an attacker with a repository mirror (the papershows that

One of the little challenges with writing Unix programs in Python isthe search path problem. The natural structure of Python programs is tosplit functionality up into a bunch of modules and then import themall in the main program, but the natural structure of a Unix program isto put its binary into one directory (such as /usr/bin ) but all ofits helper bits into a second, completely different directory. So theproblem is: how is a Unix Python program supposed to find its modules?

(The

There is a certain view, one that is easy for people to fall into,to the effect that while backwards compatibility in new versions oflanguages is important and should be given due weight, sometimes thelanguage designers can, do, and should decide that the change isimportant enough so that it should be made. Let us call this thelanguage designer view of language changes.

The problem for this view and for the decisions that come from itis simple:

Programmers do not have to accept what you give them.