An adversary sends out an ICMP Type 8 Echo Request, commonly known as a 'Ping', in order to determine if a target system is responsive. If the request is not blocked by a firewall or ACL, the target host will respond with an ICMP Type 0 Echo Reply datagram. This type of exchange is usually referred to as a 'Ping' due to the Ping utility present in almost all operating systems. Ping, as commonly implemented, allows a user to test for alive hosts, measure round-trip time, and measure the percentage of packet loss. Performing this operation for a range of hosts on the network is known as a 'Ping Sweep'. While the Ping utility is useful for small-scale host discovery, it was not designed for rapid or efficient host discovery over large network blocks. Other scanning utilities have been created that make ICMP ping sweeps easier to perform. Most networks filter ingress ICMP Type 8 messages for security reasons. Various other methods of performing ping sweeps have developed as a result. It is important to recognize the key security goal of the adversary is to discover if an IP address is alive, or has a responsive host. To this end, virtually any type of ICMP message, as defined by RFC 792 is useful. An adversary can cycle through various types of ICMP messages to determine if holes exist in the firewall configuration. When ICMP ping sweeps fail to discover hosts, other protocols can be used for the same purpose, such as TCP SYN or ACK segments, UDP datagrams sent to closed ports, etc.
Likelihood Of Attack
The table below shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.
The ability to send an ICMP type 8 query (Echo Request) to a remote target and receive an ICMP type 0 message (ICMP Echo Reply) in response. Any firewalls or access control lists between the sender and receiver must allow ICMP Type 8 and ICMP Type 0 messages in order for a ping operation to succeed.
The adversary needs to know certain linux commands for this type of attack.
Scanners or utilities that provide the ability to send custom ICMP queries.
The table below specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Consider configuring firewall rules to block ICMP Echo requests and prevent replies. If not practical, monitor and consider action when a system has fast and a repeated pattern of requests that move incrementally through port numbers.
A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful. If multiple weaknesses are associated with the attack pattern, then any of the weaknesses (but not necessarily all) may be present for the attack to be successful. Each related weakness is identified by a CWE identifier.