What is ARP Spoofing or ARP Poisoning?

Address Resolution Protocol (ARP) Spoofing

ARP Spoofing is a cyberattack that allows hackers to gain unauthorized access to your data through network layer vulnerabilities in authentication processes.

ARP stands for Address Resolution Protocol, and when devices on your network need to access a different host, they send out an ARP request packet to connect.

What is ARP Spoofing or ARP Poisoning?

ARP stands for Address Resolution Protocol and is a stateless protocol that transforms IP addresses to machine MAC (Media Access Control) addresses. When machines want to communicate on the network, they send an ARP request broadcasting their IP address and asking for its MAC. Machines then compare this response against their own. A hacker could potentially alter these messages for malicious use such as denial-of-service attacks and to gain entry to public WiFi networks.

To perform an ARP spoofing attack, hackers need to connect directly to the network – typically via being located directly next to either a router or workstation on their local area network (LAN). Once connected, they scan their network in search of two machines – say workstation and router IP addresses – then link their own MAC addresses with these IPs as ARP responses so as to cause these devices to connect instead with each other rather than with them directly.

Hackers use ARP spoofing to access all network communications and monitor every exchange that passes over it, giving them access to steal data or commit other illegal actions. By combining preventative techniques like VPNs, packet filters and encryption with more active detection technologies like ARP spoofing detection techniques you can stop this attack before much damage has been done; however, as prevention methods sometimes have flaws.

How to Detect an ARP Cache Poisoning Attack?

Much like the plot twist at the end of a thriller movie where it turns out that the main protagonist was actually evil all along, cybersecurity can often be taken by surprise by malicious parties masquerading as legitimate devices in order to achieve their nefarious goals. ARP spoofing or poisoning is one such attack which involves sending fake ARP reply messages claiming an attacker MAC address should be associated with an authentic IP address for one of your target devices; when connected via this method all traffic between victims and other machines on your network goes directly through instead of going through default gateway allowing attackers access or manipulation of data intended for machines intended for them allowing them to inspect or modify data that should have gone through its intended destination gateway instead allowing access or modification without going through its intended recipient gateway thus giving an attacker an advantage when trying to monitor or manipulate data meant for another machine without knowing.

An attacker only needs one direct link into a network to conduct an ARP spoofing attack and use tools to corrupt other machines’ ARP caches with false entries, creating chaos on their network.

An ARP Poisoning attack works by redirecting systems towards their attacker rather than each other, giving cybercriminals access to view or delete data being exchanged between systems, as well as redirect the traffic for denial-of-service attacks. An active detection tool must be employed in order to search for mapping anomalies; encryption can further reduce its impact.

What is ARP Poisoning and how does it work?

Like an action thriller plot twist, ARP Spoofing allows hackers to gain entry to local networks without leaving behind lasting infections or impacts. It can also be utilized as part of an attack campaign alongside other methods such as Man-in-the-Middle (MitM) or session hijacking attacks.

Hackers employ falsified ARP messages to pose as the default gateway and direct traffic towards their device. Once connected, an attacker can inspect, modify, or drop data packets before initiating attacks against other victims.

Computers on a LAN communicate using unique hardware addresses known as MAC addresses (Media Access Control). ARP serves to translate between these MAC addresses at the data link layer and those at the network layer – IP addresses. To speed up communication between devices, devices often announce their MAC-to-IP mappings to nearby devices using ARP; when needing this information from another device they send a request and receive back a response with this mapping information for that device – or place these entries into an ARP cache – also called an ARP table

Hackers can manipulate these cached ARP entries with false MAC-to-IP mappings and send out ARP requests to other hosts on the LAN, prompting these hosts to transmit data instead to the attacker instead of its intended destination – such as PCs or routers.

What is ARP cache poisoning attack?

ARP stands for Address Resolution Protocol and operates below OSI layer to translate IP network addresses to MAC hardware addresses, commonly employed when IPv4 is implemented over Ethernet. An ARP attack allows an attacker to alter MAC-to-IP mappings of systems on a local area network (LAN), redirecting traffic that was meant for devices belonging to others to themselves instead. This may cause confidential data leakage or cause the target system to become unresponsive, leaving behind sensitive or sensitive material behind.

This attack works by flooding a network with false ARP reply packets, causing computers in its target LAN to mistakenly update its ARP cache with attacker’s MAC address (00-00-00-00-00-2) instead of default gateway’s MAC address (0)0-00-00-00-00-00-2A and direct any future connections towards attacker’s device instead of default gateway’s device.

An attacker could intercept these communications and retrieve sensitive data or introduce malware onto their victim, potentially giving access to passwords, credit card data and personal details such as passwords or personal details that can gain control of a server or critical systems. A good way of mitigating these attacks is segmenting networks into distinct subnets so an attack on one does not impact devices in another subnet.

What is MAC Spoof?

People use MAC spoofing for both good (taking over another computer’s identity) and malicious purposes (attempting to bypass access control lists or gain free software/services). Hardware modifications may be needed in some instances; otherwise it’s as easy as downloading software that changes a device’s real MAC address into one that will connect it with certain networks.

A MAC address is unique to each network adapter and consists of six groups of two characters each (numbers or letters), separated by colons, hyphens or nothing – for instance it could look something like this D4:fb:6a:7c:31:b4.

Change Your MAC is legal; though you should exercise caution if trying to conceal your own NIC on public Wi-Fi networks. Software programs offer temporary solutions; when reset or rebooted the MAC will return to its original built-in value. Detection methods of MAC Spoofing include sequence number techniques [25, 26] operating system fingerprinting techniques as well as physical layer meta data like data rates and modulation types.

What is meant by replay attack?

Replay attacks (also called playback attacks) involve hackers intercepting network data transmissions and then retransmitting it – often without being directly on its path – without anyone knowing about it. Replay attacks allow attackers to gather credentials such as session IDs or password hashes that they can then use across the network as “impersonations of another user.”

Replay attacks are one of the more passive versions of man-in-the-middle attacks and one of the lower-tier ways hackers gain entry to networks. They require hackers to eavesdrop on communication between two users and then steal some of that information before transmitting it back through an authenticated server using it to gain entry.

As one way of protecting against replay attacks, using secure encryption protocols with strong digital signatures with timestamping can help mitigate them. You may also implement one-time passwords or require users to generate unique credentials before every communication on the network.

ARP Spoofing Prevention

Hackers can utilize ARP spoofing with either intentional or opportunistic intentions when conducting ARP spoofing attacks against your network, such as DDoS attacks. Information theft via public WiFi networks could also constitute deliberate attacks. Either way, such attacks could damage your brand and lead to significant financial losses.

Network administrators can thwart ARP spoofing attacks using ARP verification tools and monitoring network traffic, or by employing network devices with built-in ARP spoofing prevention features.

ARP serves as an intermediary between IP addresses and Media Access Control (MAC) addresses in local area networks, enabling devices to find one another based on IP. If a device receives an ARP reply containing its own MAC address, any further requests from this source will be ignored by it.

Hackers can exploit ARP packets with faked ARP packets that contain their MAC addresses to gain control of devices on a LAN by sending ARP replies that contain these packets containing fake ARP replies containing their own. As ARP is stateless and network equipment caches ARP replies, when one of these machines connects to its default gateway it assumes the attacker’s MAC address as that of their router and continues communication with it.

Sam is an experienced information security specialist who works with enterprises to mature and improve their enterprise security programs. Previously, he worked as a security news reporter.