DNSkárosodáson

DNSkárosodás, often translated as DNS poisoning or DNS cache poisoning, is a type of cyberattack where falsified Domain Name System (DNS) data is introduced into a DNS resolver's cache. This malicious data causes the resolver to return an incorrect IP address for a requested domain name, thereby redirecting users to a different, potentially malicious, website.

The attack exploits the trust placed in DNS resolvers. When a user attempts to access a website, their computer queries a DNS resolver for the corresponding IP address. If the resolver's cache has been poisoned, it will provide the attacker's IP address instead of the legitimate one. This can lead to users unknowingly visiting phishing sites, downloading malware, or having their sensitive information intercepted.

There are several methods to carry out DNSkárosodás. One common technique is cache snooping, where an attacker sends forged DNS responses to a resolver, attempting to match a query it is currently processing. Another method involves compromising the authoritative DNS server for a domain, allowing the attacker to directly alter the DNS records. The consequences of a successful DNSkárosodás attack can include financial loss, identity theft, and reputational damage for organizations. Countermeasures include using DNSSEC (Domain Name System Security Extensions) to authenticate DNS responses and implementing security measures on DNS servers to prevent unauthorized access and data modification.