up:: [[Man-in-the-middle attacks]] # ARP Spoofing ARP Spoofing, also known as ARP Poisoning, is a type of cyber attack where an attacker sends falsified [[ARP (Address Resolution Protocol)]] messages onto a local area network (LAN). This attack exploits the lack of authentication in the ARP protocol, allowing the attacker to associate their MAC address with the IP address of another device (such as the default gateway), effectively intercepting, altering, or disrupting network traffic. ## Key Features - **ARP Protocol**: ARP is used to map IP addresses to MAC addresses on a local network. Devices on the network use ARP to discover the MAC address of another device to which they want to send data. - **Spoofing Attack**: In ARP spoofing, the attacker sends forged ARP replies to the network, misleading devices into associating the attacker’s MAC address with the IP address of another device. - **Man-in-the-Middle (MitM)**: ARP spoofing is often used as a stepping stone to MitM attacks, where the attacker intercepts and potentially alters communications between devices. - **Network Disruption**: Besides eavesdropping, ARP spoofing can also be used to disrupt network traffic, leading to denial-of-service (DoS) conditions. ## Problem Addressed ARP Spoofing targets the vulnerability in the ARP protocol, which lacks authentication mechanisms. This allows attackers to manipulate the ARP tables of devices on a network, enabling them to intercept, modify, or stop network traffic. ## Implications ARP Spoofing can have severe implications, including unauthorized access to sensitive data, network disruptions, and the facilitation of more complex attacks like session hijacking and data exfiltration. In corporate environments, ARP spoofing can lead to significant data breaches and loss of business continuity. ## Impact - **Data Interception**: Attackers can capture sensitive information, such as login credentials, personal data, and financial transactions. - **Session Hijacking**: By intercepting session tokens, attackers can impersonate users and gain unauthorized access to systems. - **Denial of Service**: ARP spoofing can disrupt network communications, leading to loss of connectivity and services. - **Network Performance Degradation**: Manipulating network traffic can lead to slowdowns and increased latency, affecting the performance of network services. ## Defense Mechanisms - **Static ARP Entries**: Configuring static ARP entries on critical devices can prevent them from accepting malicious ARP replies. - **ARP Inspection**: Dynamic ARP Inspection (DAI) is a security feature that intercepts and validates ARP packets on the network, ensuring that only valid requests and replies are allowed. - **Encryption**: Encrypting network traffic (e.g., using HTTPS, VPNs) reduces the impact of ARP spoofing, as intercepted data remains unreadable without decryption keys. - **Network Segmentation**: Isolating critical systems and limiting broadcast domains can reduce the attack surface for ARP spoofing. - **Monitoring Tools**: Implementing network monitoring tools that can detect unusual ARP traffic or changes in the ARP tables can help identify and mitigate spoofing attacks. ## Exploitable Mechanisms/Weaknesses - [[Using ARP spoofing to intercept network traffic]] - **Lack of ARP Authentication**: ARP does not authenticate requests or replies, making it susceptible to spoofing attacks. - **Broadcast Nature of ARP**: ARP requests are broadcast to all devices on a local network, allowing an attacker to easily inject forged responses. - **Unsecured Networks**: Networks lacking proper segmentation or security measures are more vulnerable to ARP spoofing. - **Outdated Network Equipment**: Older network equipment may not support modern security features like Dynamic ARP Inspection, making them more susceptible to spoofing attacks. ## Common Tools/Software - **Ettercap**: A comprehensive tool for network attacks, including ARP spoofing and MitM attacks. - **Cain & Abel**: A password recovery tool for Windows that also includes features for ARP spoofing. - **BetterCAP**: A powerful network attack tool that supports ARP spoofing, packet capture, and network analysis. - **Wireshark**: A network protocol analyzer that can be used to detect ARP spoofing by monitoring ARP traffic for anomalies. ## Current Status ARP Spoofing remains a prevalent threat, particularly in unsecured or poorly managed networks. As networks evolve, newer security protocols and tools are being implemented to mitigate the risk of ARP spoofing, such as Dynamic ARP Inspection and enhanced network segmentation. However, the lack of inherent security in the ARP protocol itself means that vigilance and proactive network management are essential to prevent these attacks. ## Revision History - **2024-08-03**: Initial creation of the entry, detailing ARP spoofing, its mechanics, and methods to defend against it.