問56
頻出度★★★
インターネットにおいてドメイン名とIPアドレスの対応付けを行うサービスを提供しているサーバに保管されている管理情報を書き換えることによって，利用者を偽のサイトへ誘導する攻撃はどれか。
令和3年度 ITパスポート試験 問56
テクノロジ系セキュリティ › 情報セキュリティ
This question's explanation and your answers so far.
解説
問 56
Incorrectア
A DDoS attack sends a huge volume of traffic from many devices all at once to overload the target server or network and stop its service. Its aim is to take away availability; it is not an attack that rewrites management information to lure users to a fake site, so it is incorrect.
- イ
正解 The “server that provides the service of mapping domain names to IP addresses” mentioned in the question refers to a DNS server. DNS Cache Poisoning is an attack that rewrites the name-resolution management information stored on this DNS server (especially the caching DNS server) with fake information the attacker has prepared. Once it is poisoned, even if a user enters the correct domain name, a fake IP address is returned, luring the user to a fake site that looks just like the real one. Because it matches exactly the two features of “rewriting the management information” and “luring users to a fake site,” the correct answer is イ.
Incorrectウ
SQL Injection injects malicious SQL statements into input fields of a web application and illicitly manipulates the backend database to steal or tamper with information. Its target is the database, not rewriting the DNS mapping information to lure users to a fake site, so it is incorrect.
Incorrectエ
Phishing tricks users, through email or SMS disguised as legitimate, into clicking a link to a fake site and entering information such as their ID and password so it can be stolen. Although it is similar in that it deceives and lures users, it does not “rewrite” the management information on a DNS server, so it does not match the description in the question and is incorrect.
ここがポイント
- DNS is the mechanism that maps domain names to IP addresses (performs name resolution), and the attack that rewrites this information is DNS Cache Poisoning.
- A characteristic of DNS Cache Poisoning is that a poisoned DNS server returns a fake IP address, luring users to a fake site without their noticing.
用語