Remediations for Host Risks
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.. _Risk 001:

SMTP Server Contacts
====================
#. Implement Firewalls and Intrusion Prevention Systems (IPS): Use firewalls and intrusion prevention systems (IPS) to filter and block traffic from known sources of suspected spam or excessive SMTP activity. By doing so, you can prevent unauthorized entities from contacting multiple SMTP servers.
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit the number of users who have permission to send emails using your organization's SMTP servers. By doing so, you can reduce the risk of unauthorized users sending spam or excessive email traffic to external servers.
#. Implement Sender Policy Framework (SPF): Use SPF records in DNS to specify which IP addresses are authorized to send email on behalf of your domain. By doing so, you can prevent spoofed emails and limit the number of servers that can be contacted from your domain.
#. Implement Greylisting: Implement greylisting to delay delivery of emails from unknown or suspicious sources for a short period of time. By doing so, you can reduce the volume of unsolicited email traffic and limit the number of SMTP servers that are contacted by a single entity.

.. _Risk 002:

DNS Traffic
===========
#. Implement DNS Server Filtering: Set up a firewall or intrusion prevention system (IPS) to filter and block requests from a single entity that exceeds the threshold limit of DNS queries. You can configure the firewall or IPS to drop or limit the traffic based on source IP addresses, query types, or other relevant factors.
#. Implement DNS Rate Limiting: DNS rate limiting is a technique used to control the number of queries that can be made by a single entity to a DNS server within a specified time frame. By implementing DNS rate limiting, you can prevent a single entity from overwhelming your DNS infrastructure with excessive queries.
#. Implement DNS Reputation Filtering: DNS reputation filtering is a technique used to block traffic from known malicious or suspicious sources based on their DNS query behavior. By implementing DNS reputation filtering, you can prevent queries from entities that exhibit abnormal or malicious behavior and reduce the risk of exceeding the threshold limit due to such requests.
#. Implement DNS Query Logging and Analysis: Regularly review your DNS query logs to identify any unusual patterns or trends in query traffic. By analyzing the logs, you can identify entities that are making excessive queries and take appropriate action to remediate the situation. This approach helps improve network security while ensuring that DNS servers remain responsive and performant.

.. _Risk 003:

NTP Server Contacts
===================
#. Implement NTP Source Filtering: Use firewalls or intrusion prevention systems to filter and block NTP traffic from sources that are not on an approved list. By implementing source filtering, you can prevent a single entity from contacting too many different NTP servers.
#. Implement Rate Limiting: Use rate limiting to limit the amount of NTP traffic that a particular IP address or device can send or receive within a specific time frame. By implementing rate limiting, you can prevent excessive NTP traffic and ensure that your network resources are not being consumed by a single entity.
#. Implement Access Control: Use access control lists (ACLs) to restrict access to your NTP servers based on IP addresses or subnets. By implementing access control, you can limit the number of entities that can contact your NTP servers and prevent any one entity from exceeding the threshold limit.
#. Implement Network Segmentation: Use network segmentation to isolate your NTP servers from other parts of your network. By doing so, you can limit the exposure of your NTP servers to external threats and prevent a single entity from contacting too many different NTP servers within your network.

.. _Risk 004:

Flows Flood
===========
#. Traffic Filtering: This is a fundamental security measure that can help prevent excessive traffic from entering the network. Firewalls, intrusion prevention systems (IPS), and other traffic filtering solutions are commonly used to block or restrict access to identified malicious or anomalous traffic.
#. Rate Limiting: Rate limiting is another important technique for managing network traffic and preventing a single source from overwhelming the network with excessive traffic. It can help reduce the impact of a flow flood attack by limiting the amount of traffic that can be sent or received by a particular device or application within a specific time frame.
#. Network Segmentation: Network segmentation is an effective way to isolate critical devices or applications from the rest of the network, preventing an attack on one device or application from spreading to other parts of the network and reducing the overall impact of a flow flood attack.
#. DDoS Protection: Distributed Denial of Service (DDoS) protection is becoming increasingly important as more organizations rely on the internet for critical services. A DDoS protection service can help absorb and mitigate the impact of a flow flood attack by distributing the traffic across multiple servers or networks, ensuring that services remain available.
#. Use nScrub

.. _Risk 005:

TCP SYN Scan
============
#. Implement Firewalls and Intrusion Prevention Systems (IPS): Use firewalls and intrusion prevention systems (IPS) to filter and block TCP traffic with suspicious SYN flags or patterns. By doing so, you can prevent unauthorized attempts to conduct a SYN scan on your network.
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit the number of users who have permission to perform port scans or other network reconnaissance activities. By doing so, you can reduce the attack surface and minimize the risk of insider threats or accidental exposures.
#. Implement Rate Limiting: Implement rate limiting for incoming TCP traffic to limit the number of connection requests per second or minute from a single source. By doing so, you can prevent excessive traffic that could potentially be used for SYN scans or other types of Denial-of-Service (DoS) attacks.
#. Implement SYN Cookies: Use SYN cookies to prevent half-open connections and reduce the risk of SYN scans. SYN cookies are a way to simulate a full three-way handshake without completing the connection, allowing the targeted system to identify and terminate malicious traffic more effectively.

.. _Risk 006:

TCP SYN Flood
=============
#. Implement Syn Cookies: Use syn cookies, which are small pieces of data sent by the server to the client during TCP handshaking, to help prevent SYN flood attacks. By implementing syn cookies, you can reduce the memory consumption on your servers and allow them handle more simultaneous connections without being overwhelmed.
#. Implement Rate Limiting: Use rate limiting to limit the number of new connections that a particular IP address or device can establish within a specific time frame. By implementing rate limiting, you can prevent a single entity from establishing too many connections at once and overwhelming your network resources.
#. Implement Filtering: Use firewalls or intrusion prevention systems to filter and block SYN packets from sources that are not on an approved list or that exhibit suspicious behavior. By doing so, you can prevent unauthorized access attempts and reduce the risk a SYN flood attack.
#. Use nScrub

.. _Risk 007:

Domain Names Contacts
=====================
#. Implement DNS Filtering: Use a DNS filtering solution to block or restrict access to domains that are not authorized or that exhibit suspicious behavior. By implementing DNS filtering, you can prevent unauthorized queries and reduce the risk of excessive traffic from a single entity.
#. Implement Domain Name System (DNS) Reputation Filtering: Use a DNS reputation filtering solution to block access to domains that have been identified as malicious or suspicious based on their past behavior or known associations with cyber threats. By implementing DNS reputation filtering, you can prevent queries to unauthorized domains and reduce the risk of excessive traffic from a single entity.
#. Implement Domain Name System (DNS) Rate Limiting: Use DNS rate limiting to limit the number of queries that can be made by a single entity to different domains within a specific timeframe. By implementing DNS rate limiting, you can prevent a single entity from overwhelming your DNS infrastructure and ensure that all legitimate requests are processed in a timely manner.
#. Implement Domain Name System (DNS) Query Logging and Analysis: Use DNS query logging and analysis tools to monitor traffic patterns and trends for queries to different domains. By analyzing logs and reports, you can identify anomalous behavior or unauthorized ries and take appropriate action to remediate the situation.

.. _Risk 012:

Remote Connection
=================
#. Implement Strong Access Control: Use strong access control mechanisms to restrict access to your remote access servers based on IP addresses, user accounts, and multi-factor authentication. By doing so, you can prevent unauthorized access attempts and reduce the risk of potential security threats.
#. Implement Rate Limiting: Use rate limiting to limit the number of concurrent connections that a particular IP address or user account can establish within a specific time frame. By implementing rate limiting, you can prevent excessive usage and ensure that your network resources are not being consumed by a single entity.
#. Implement Network Segmentation: Use network segmentation to isolate your remote access servers from other parts of your network. By doing so, you can limit the exposure of your remote access infrastructure to external threats and prevent unauthorized access attempts or excessive usage.
#. Implement Encryption: Use strong encryption protocols such as Advanced Encryption Standard (AES) or Rivest-Shamir-Adleman (RSA) to secure data transmitted over remote access sessions. By doing so, you can help ensure that sensitive information is protected from interception and unauthorized access.

.. _Risk 013:

Host Log
========
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit the number of users who have permission to send SNMP requests to your network devices. By doing so, you can reduce the attack surface and minimize the risk of unauthorized entities conducting a SNMP flood.
#. Implement Rate Limiting: Implement rate limiting for SNMP requests to limit the number of requests per second or minute from a single source. By doing so, you can prevent excessive traffic that could potentially overwhelm your network devices and make them unresponsive or crash.
#. Implement Traffic Filtering: Use firewalls and intrusion prevention systems (IPS) to filter and block SNMP requests from known sources of attack or suspicious activity. By doing so, you can prevent unauthorized attempts to conduct a SNMP flood on your network.
#. Implement SNMP Version Control: Upgrade to the latest version of SNMP and disable older insecure versions. Older versions of SNMP have known vulnerabilities that could be exploited by attackers to conduct a SNMP flood or other types of attacks.
#. Implement SNMP Trap Filtering: Use trap filtering to limit the number of devices that can send unsolicited SNMP traps to your management station. By doing so, you can prevent excessive traffic generated by rogue devices or compromised systems.

.. _Risk 016:

Countries Contacts
==================
#. Implement Firewalls and Intrusion Prevention Systems (IPS): Use firewalls and intrusion prevention systems (IPS) to filter and block traffic based on IP addresses from known sources of suspicious activity or excessive outbound traffic to different countries. By doing so, you can prevent unauthorized attempts to contact too many servers in different countries.
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit the number of users who have permission to send traffic to external servers in different countries. By doing so, you can reduce the risk of insider threats or accidental exposures that could result in excessive outbound traffic.
#. Implement Traffic Filtering: Use content filtering and traffic shaping technologies to identify and limit outbound traffic to specific countries based on certain criteria such as protocol, port, or payload. By doing so, you can prevent unintended traffic or malicious activity from being sent to servers in different countries.
#. Implement Incident Response Planning: Have a well-defined incident response plan in place to ensure that your organization is prepared to respond effectively to any potential violation of the limit on contacting servers in different countries. This should include procedures for investigating and mitigating the impact of excessive outbound traffic, communicating with affected parties, and taking appropriate disciplinary actions against offending users or systems.

.. _Risk 018:

ICMP Flood
==========
#. Implement ICMP Filtering: Use firewalls, intrusion prevention systems (IPS), or other security appliances to filter and block ICMP traffic based on specific criteria such as IP address, port number, or message type. By implementing ICMP filtering, you can prevent excessive ICMP traffic from entering your network and disrupting services.
#. Implement Rate Limiting: Use rate limiting to limit the amount of ICMP traffic that can be sent or received by a particular device or application within a specific time frame. By implementing rate limiting, you can prevent a single source from overwhelming your network with excessive ICMP traffic during an attack.
#. Implement IP Address Filtering: Use access control lists (ACLs) or other security mechanisms to block or limit ICMP traffic from specific sources or destinations. By implementing IP address filtering, you can prevent ICMP traffic from known malicious sources from reaching your network and disrupting services.
#. Implement Packet Filtering: Use packet filtering techniques to drop packets that are identified as ICMP floods based on specific criteria such as packet size, repetition rate, or source/destination IP addresses. By implementing packet filtering, you can prevent excessive ICMP traffic from entering your network and causing disruptions.
#. Use nScrub

.. _Risk 020:

Scan Detected
=============
#. Implement Firewalls and Intrusion Prevention Systems (IPS): Use firewalls and intrusion prevention systems to filter and block traffic from known sources of network scans or suspicious activity. By doing so, you can prevent unauthorized probes and reconnaissance activities from reaching your network.
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit access to sensitive areas of your network. By doing so, you can reduce the attack surface and minimize the risk of unauthorized access or reconnaissance activities.
#. Implement Network Segmentation: Use network segmentation to isolate critical areas of your network from other parts of the network. By doing so, you can limit the exposure of sensitive resources and make it more difficult for scanners or attackers to gain a foothold in your network.
#. Implement Network Honeypots: Use network honeypots to attract and analyze potentially malicious traffic. By doing so, you can gain valuable insights into the motives and techniques of attackers and improve your network security defenses.

.. _Risk 021:

TCP FIN Scan
============
#. Implement Firewalls and Intrusion Prevention Systems (IPS): Use firewalls and intrusion prevention systems (IPS) to filter and block Fin packets from known sources of attack or suspicious activity. By doing so, you can prevent unauthorized attempts to conduct a scan on your network.
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit access to sensitive areas of your network. By doing so, you can reduce the attack surface and minimize the risk of unauthorized users attempting a Fin scan.
#. Implement Network Segmentation: Use network segmentation to isolate critical areas of your network from other parts of the network. By doing so, you can limit the exposure of sensitive resources and make it more difficult for attackers to launch a Fin scan.

.. _Risk 022:

DNS Flood
=========
#. Implement Rate Limiting: Set up rate limiting on your DNS servers to restrict the number of queries per unit time from a single source IP address or domain name. This can help prevent excessive traffic and reduce the risk of being overwhelmed by a flood attack. 
#. Use DNSSEC: Implement DNS Security Extensions (DNSSEC) to add an extra layer of security to your DNS infrastructure. This helps protect against cache poisoning, which can redirect users to malicious websites or intercept their data during transit
#. Use nScrub

.. _Risk 023:

SNMP Flood
==========
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit the number of users who have permission to send SNMP requests to your network devices. By doing so, you can reduce the attack surface and minimize the risk of unauthorized entities conducting a SNMP flood.
#. Implement Rate Limiting: Implement rate limiting for SNMP requests to limit the number of requests per second or minute from a single source. By doing so, you can prevent excessive traffic that could potentially overwhelm your network devices and make them unresponsive or crash.
#. Implement Traffic Filtering: Use firewalls and intrusion prevention systems (IPS) to filter and block SNMP requests from known sources of attack or suspicious activity. By doing so, you can prevent unauthorized attempts to conduct a SNMP flood on your network.
#. Implement SNMP Version Control: Upgrade to the latest version of SNMP and disable older insecure versions. Older versions of SNMP have known vulnerabilities that could be exploited by attackers to conduct a SNMP flood or other types of attacks.
#. Implement SNMP Trap Filtering: Use trap filtering to limit the number of devices that can send unsolicited SNMP traps to your management station. By doing so, you can prevent excessive traffic generated by rogue devices or compromised systems.

.. _Risk 025:

TCP RST Scan
============
#. Implement Firewalls and Intrusion Prevention Systems (IPS): Use firewalls and intrusion prevention systems (IPS) to filter and block RST packets from known sources of attack or suspicious activity. By doing so, you can prevent unauthorized attempts to disrupt your network traffic.
#. Implement Access Control: Use access control mechanisms such as strong passwords, multi-factor authentication, and role-based access control to limit access to sensitive areas of your network. By doing so, you can reduce the attack surface and minimize the risk of unauthorized users attempting a RST scan.
#. Implement Network Segmentation: Use network segmentation to isolate critical areas of your network from other parts of the network. By doing so, you can limit the exposure of sensitive resources and make it more difficult for attackers to launch a RST scan.







