IP forwarding for IPv4 must not be enabled, unless the system is a router.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-12023	GEN005600	SV-35177r1_rule	ECSC-1	Medium

Description
If the system is configured for IP forwarding and is not a designated router, it could be used to bypass network security by providing a path for communication not filtered by network devices.

STIG	Date
HP-UX 11.31 Security Technical Implementation Guide	2017-12-08

Details

Check Text ( C-36675r1_chk )
The configuration file entries will appear as follows: TRANSPORT_NAME[x]=ip NDD_NAME[x]=ip_forwarding NDD_VALUE[x]=0 NOTE: The setting for the "ip_forwarding" interface will be initialized on a separate line referencing a specific NDD index. # cat /etc/rc.config.d/nddconf \| tr '\011' ' ' \| tr -s ' ' \| sed -e 's/^[ \t]//' \| grep -v '^#' \| \ grep -i ip_forwarding \| cut -f 1,1 -d "=" \| tr -d [:alpha:] \| tr -d [:punct:] If the above command returns nothing, this check is not a finding. If the above command does return an index value: # cat /etc/rc.config.d/nddconf \| tr '\011' ' ' \| tr -s ' ' \| sed -e 's/^[ \t]//' \| grep -v '^#' \| \ grep "[the ip_forwarding INDEX number from the above command]" NOTE: The above command must (literally) contain the ASCII punctuation characters [ and ] exactly as depicted above. If the return value is not set to 0, ask the SA if the machine is a designated router. If it is not a designated router, this is a finding. If it is a designated router, this is not a finding.

Check Text ( C-36675r1_chk )

The configuration file entries will appear as follows:
TRANSPORT_NAME[x]=ip
NDD_NAME[x]=ip_forwarding
NDD_VALUE[x]=0
NOTE: The setting for the "ip_forwarding" interface will be initialized on a separate line referencing a specific NDD index.

# cat /etc/rc.config.d/nddconf | tr '\011' ' ' | tr -s ' ' | sed -e 's/^[ \t]*//' | grep -v '^#' | \
grep -i ip_forwarding | cut -f 1,1 -d "=" | tr -d [:alpha:] | tr -d [:punct:]

If the above command returns nothing, this check is not a finding.

If the above command does return an index value:
# cat /etc/rc.config.d/nddconf | tr '\011' ' ' | tr -s ' ' | sed -e 's/^[ \t]*//' | grep -v '^#' | \
grep "[the ip_forwarding INDEX number from the above command]"

NOTE: The above command must (literally) contain the ASCII punctuation characters [ and ] exactly as depicted above.

If the return value is not set to 0, ask the SA if the machine is a designated router. If it is not a designated router, this is a finding. If it is a designated router, this is not a finding.

Fix Text (F-32046r1_fix)
Edit /etc/rc.config.d/nddconf and set the ip_forwarding option to 0.