The Cisco ASA must be configured to filter inbound traffic on all external interfaces.
An XCCDF Rule
Description
<VulnDiscussion>Unrestricted traffic to the trusted networks may contain malicious traffic that poses a threat to an enclave or to other connected networks. Additionally, unrestricted traffic may transit a network, which uses bandwidth and other resources. Firewall filters control the flow of network traffic, ensure the flow of traffic is only allowed from authorized sources to authorized destinations. Networks with different levels of trust (e.g., the Internet) must be kept separated.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-239865r855807_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Step 1: Configure the ACL to allow specific inbound traffic.
ASA(config)# access-list OUTSIDE_2_DMZ extended permit tcp any host 10.1.33.2 eq www
ASA(config)# access-list OUTSIDE_2_DMZ extended permit tcp any host 10.1.33.2 eq https
ASA(config)# access-list OUTSIDE_2_DMZ extended permit tcp any host 10.1.33.3 eq ftp
ASA(config)# access-list OUTSIDE_2_DMZ extended permit tcp any host 10.1.33.3 eq ftp-data