BUG #4433: entries like "host all all 10.0.50.31/0 ..." should not be allowed or trigger a warning

The following bug has been logged online:

Bug reference:      4433
Logged by:          security  improvement proposal: pg_hba.conf and CIDR
mask
Email address:      marc@intershop.de
PostgreSQL version: 8.2.4
Operating system:   Linux
Description:        entries like "host    all       all   10.0.50.31/0  ..."
should not be allowed or trigger a warning
Details:

Hello,

not really a bug, but a possible security issue for wrongly configured
installations.

A CIDR mask length of 0 will allow to connect from any location. I did this
mistake as I didn't read the documentation carefully enough.

Checking the mask against the IP address would prevent such errors:

/0 : disallow ?

/24 : IP must ends with .0
/16 : IP must ends with .0.0
...

HTH,

Marc Mamin