IP Spoofing Unraveled: What It Is & How to Prevent It
Internet protocol spoofing (or IP spoofing) involves impersonation. A hacker alters address data within the IP header, fooling a system into believing the data comes from a trusted source.
People use IP spoofing to launch devastating attacks, including denial of service (DOS) and man in the middle. But the technique also has legitimate uses, especially if you're planning to launch a new website.
It's difficult to stop an IP spoofing attack in progress. But with filtering techniques and solutions applied on the edge of your network, you can stop a hacker from gaining access.
How IP Spoofing Works
Hackers exploit known vulnerabilities to launch an attack. Then, they use bots or zombie computers to amplify their work. The results can be catastrophic.
Each time you send something between servers, the data is bundled into packets. Each one comes with a header, and that typically includes routing information, such as the sender's address. Once all the packets reach their destination, they're reassembled and combined into a cohesive whole.
In a typical network, outgoing traffic isn't subject to a filter or a cross-checking system. Inconsistencies flit by, and the system isn't designed to look for them.
To accomplish IP spoofing, a hacker typically needs:
- A trusted connection. Spoofs work best between two devices that have some kind of prior relationship. If a hacker can access an internal machine that doesn't require a login, the attack is much easier to launch.
- A controlled IP. The hacker must have an address that can be ignored.
- Coding know-how. The hacker must know how to intercept a packet and swap out the address in the IP header.
With this work completed, you will be unable to:
- Stop the attack. Block the IP address that seems to be the source, and you'll block work from a benign computer. You'll have no idea where the problem originates.
- Respond to the attack. You won't know to whom you should speak or what to do next, as you won't have the proper address.
IP spoofing is relatively common. It takes just a bit of know-how to launch an attack, and once inside, the rewards are significant.
What Is IP Spoofing Used For?
Anyone with a desire to cause destruction and disorder could attempt to spoof an IP address. But it's typically used for one of two reasons.
Hackers use IP spoofing to conduct serious and overwhelming attacks, such as:
- Denial of service. Once the hacker forms a connection between a falsified address and your server, it's time to launch a series of requests. Hackers may send just a few at first, but amplifying the attack through open reflectors, such as servers running applications with connectionless protocols, can be devastating.
Experts say an attack like this can reach several hundred Gbps. Your system won't have the capacity to do anything else.
- Man in the middle. Once hackers establish a trusted connection, they can reroute all packets to a destination they choose. All data could be read or manipulated before it's released.
IP spoofing, as a whole, isn't illegal. You may have legitimate reasons for deploying the technique within your own server.
For example, if you're preparing to launch a new website, you must understand how it will perform when hit by hundreds or even thousands of website visitors from all around the globe. IP spoofing could allow you to run simulations to enhance your performance and ensure that your site stays up.
You might also run IP spoofing simulations to check for gaps within your programmed security systems. If you can't run a test, you may never know if you have adequate protections in place.
How to Protect Against an IP Spoofer
Cyberattacks cost businesses an average of $200,000 per incident. Since IP spoofing is one of the easiest attacks to launch, and one of the most devastating, it makes sense to put protection at the top of your to-do list.
These are commonsense solutions:
- Use filters. Set up systems to examine the source headers of incoming IP packets. If something looks unusual or awry, reject those packets outright until the