Learn in the textbookTechnical and Physical Vulnerabilities
DefinitionA security hole (セキュリティホール) is a weakness in software or a system, caused by a bug or a design flaw, that attackers can exploit.
ExplanationA weakness that attackers can take advantage of is called a vulnerability (脆弱性), and a security hole is the typical example. The fix a developer releases to close the hole is a security patch (セキュリティパッチ), and applying it early to keep software current is the basic countermeasure. An attack that strikes the hole before any fix is released is a zero-day attack (ゼロデイ攻撃), and patching alone cannot fully stop it.
AnalogyIt is like a small crack in the wall around a house. The family may never notice it, but a burglar will find it and slip in. Sealing it early is the basic defense.
Memory hookA hole is a gap, and a patch is the cloth sewn over a hole in clothing. Remember them as a pair: every hole gets a patch.