Re: [cobalt-security] FTPD DoS

[John Bailey <support@xxxxxxxxxxxxxxxxxxxxxx>]

> Well, hopefully your users wouldn't crash the RaQ on purpose.  There's
> millions of ways to crash Linux at any rate, mostly due to lack of
> process restrictions in the Linux kernel.

PAM can used to implement process number (and other) limits in the Linux
Kernel.  Take a look at

http://www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam-6.html#ss6.12

for more details.  This can certainly be used to prevent fork-bombs and
the like.

> All reproducable via PHP/Perl etc...

PHP does have some facilities to prevent users doing nasty things.  Take a
look at the 'disable_function', 'max_execution_time' and 'memory_limit'
configuration directives for good examples.

Regards,

John