no argv

[Topi Miettinen <Topi Miettinen medialab sonera net>]

Running programs (including set?id ones) without argv (execle(f,0,0))
causes many of them to die with a segmentation violation when they blindly
try to access argv[0]. 

This could be exploited in denial-of-service attacks if the program has
opened a lock file before segfaulting, though I haven't found any yet. I
can't think of a way for this to give a root shell.

-Topi