Bug 1609014

Description of problem:
The below section causes all incoming traffic to be accepted.

Location in https://static.open-scap.org/ssg-guides/ssg-rhel7-guide-index.html  (Profile: DISA STIG )

     firewalld > Strengthen the Default Ruleset > Configure firewalld To Rate Limit Connections



Configure firewalld To Rate Limit Connections:
==============================================

Configure firewalld To Rate Limit Connections   [ref]rule

Create a direct firewall rule to protect against DoS attacks with the following command:

$ sudo firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT_direct 0 -p tcp -m limit --limit 25/minute --limit-burst 100  -j ACCEPT

Rationale:

DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity.

This requirement addresses the configuration of the operating system to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exist to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks.


Version-Release number of selected component (if applicable):
Current version: 0.1.40


How reproducible:
Every time


Steps to Reproduce:
1.# firewall-cmd --set-default-zone=drop
2.# firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT_direct 0 -p tcp -m limit --limit 25/minute --limit-burst 100  -j ACCEPT
3.# firewall-cmd --reload


Actual results:
All traffic is accepted

Expected results:
Anything that is not explicitly open to be dropped

Additional info:

If the command is change to -j INPUT_ZONES in stead of -j ACCEPT the traffic is rate limited as expected and the packets are filtered by the zones as intended. 

     # firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT_direct 0 -p tcp -m limit --limit 25/minute --limit-burst 100  -j INPUT_ZONES

[root@firewalld ~]# firewall-cmd --perm --set-default-zone=drop
[root@firewalld ~]# firewall-cmd --perm --add-service=ssh
[root@firewalld ~]# firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT_direct 0 -p tcp -m limit --limit 25/minute --limit-burst 100  -j INPUT_ZONES
[root@firewalld ~]firewall-cmd --reload
[root@firewalld ~]# nc -l 5255 &

[root@firewalld-client ~]# nc 10.12.214.19 5255
Ncat: Connection timed out.

[root@firewalld-client ~]# nc 10.12.214.19 22
SSH-2.0-OpenSSH_7.4

[root@firewalld ~]# iptables -vnxL 
----------------snip-------------------------
Chain INPUT_direct (1 references)
    pkts      bytes target     prot opt in     out     source               destination         
       9      540 INPUT_ZONES  tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            limit: avg 25/min burst 100


Chain INPUT_ZONES (2 references)
    pkts      bytes target     prot opt in     out     source               destination         
     166    22758 IN_drop    all  --  eth0   *       0.0.0.0/0            0.0.0.0/0           
       0        0 IN_drop    all  --  +      *       0.0.0.0/0            0.0.0.0/0     

Chain IN_drop (2 references)
    pkts      bytes target     prot opt in     out     source               destination         
     166    22758 IN_drop_log  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
     166    22758 IN_drop_deny  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
     166    22758 IN_drop_allow  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
     165    22698 DROP       all  --  *      *       0.0.0.0/0            0.0.0.0/0  

Chain IN_drop_allow (1 references)
    pkts      bytes target     prot opt in     out     source               destination         
       1       60 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            tcp dpt:22 ctstate NEW         




Chain INPUT_ZONES (1 references)
 pkts bytes target     prot opt in     out     source               destination         
 5842  412K IN_drop    all  --  ens192 *       0.0.0.0/0            0.0.0.0/0           
    0     0 IN_drop    all  --  +      *       0.0.0.0/0            0.0.0.0/0    

Chain IN_drop (2 references)
 pkts bytes target     prot opt in     out     source               destination         
 5842  412K IN_drop_log  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
 5842  412K IN_drop_deny  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
 5842  412K IN_drop_allow  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
 1084  154K DROP       all  --  *      *       0.0.0.0/0            0.0.0.0/0