On 12/10/2015 07:01 AM, [email protected] wrote:
Hello folks,
I am new here, so I am not sure if this was discussed and closed earlier. If
so, I am sorry for bringing it up again.
I notice that some of the OVAL checks and remediation scripts for network-kernel parameters seem to
ignore the XCCDF input variable. For example, the rule
"sysctl_net_ipv4_conf_all_accept_source_route" has an associated XCCDF variable
"sysctl_net_ipv4_conf_all_accept_source_route_value" which it seems to be passing to the
OVAL check:
<oval id="sysctl_net_ipv4_conf_all_accept_source_route"
value="sysctl_net_ipv4_conf_all_accept_source_route_value" />
However, the OVAL check and remediation script seem to be ignoring it:
<unix:sysctl_state id="state_runtime_net_ipv4_conf_all_accept_source_route"
version="1">
<unix:value datatype="int" operation="equals">0</unix:value>
</unix:sysctl_state>
Fix:
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_source_route=0
This is a problem only when someone decides to alter the default variable value from "disabled" to
"enabled", which I understand is not very likely. Nevertheless, someone using
"refine-value" gets an incorrect evaluation and remediation result.
I would like to fix this but I am not sure what is the right way forward. Most of these sysctl
parameters are binary valued and one of those is the conventional "good" value you'd
expect. So unless these XCCDF variables are here for a reason, the simplest solution (I would
assume) is to remove these XCCDF variables altogether and just evaluate against the
"good" value.
The other approach would be to make OVAL and the fix use the variable. The OVAL
sysctl_state's value field should be able to refer to an external variable if I
am not mistaken.
Please let me know what you think.
Thank you for your time.
Best Regards,
Gautam.
You are very right in your conclusions, Gautam.
I don't know why the XCCDF:value exists in the first place in this case.
However, I would proceed with fixing the OVAL to respect the XCCDF:value.
You need to change the sysctl_state
<unix:value datatype="int" operation="equals">0</unix:value>
to something like
<unix:value datatype="int"
operation="equals"var_ref="sysctl_net_ipv4_conf_all_accept_source_route_value"
var_check="all"/>
~š.
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