2nd/10_Wiki/Dev/Topic_SQL/SQL_Injection.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
sql-injection	SQL Injection	Database	draft	conceptual		SQL 인젝션		B	0.87	2026-07-04	2026-07-04			sql database w3schools security injection	https://www.w3schools.com/sql/sql_injection.asp

SQL Injection

🎯 한 줄 통찰 (One-line insight)

SQL injection exploits raw string concatenation of user input into a query — a tautology like OR 1=1 or a batched ; DROP TABLE ... can turn a single-row lookup into a full-table dump or destructive command. [S1]

🧠 핵심 개념 (Core concepts)

• SQL injection — a code injection technique where attackers insert malicious SQL into user-input fields to read, modify, or delete sensitive data. [S1]
• Root cause — building SQL strings by concatenating raw user input, e.g. txtSQL = "SELECT * FROM Users WHERE UserId = " + txtUserId;. [S1]
• Tautology injection (1=1) — input like 105 OR 1=1 makes the WHERE clause always true, returning every row. [S1]
• Tautology injection (""="") — the same idea applied to string-quoted login fields (" OR ""="), bypassing username/password checks entirely. [S1]
• Batched statement injection — a semicolon lets an attacker append an entirely separate destructive statement, e.g. UserId = 105; DROP TABLE Suppliers;. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Never trust concatenated input — every example in the source traces back to the same root cause: building a SQL string by directly concatenating unescaped, unvalidated user input. [S1]
• The fix lives in the next two chapters — the source explicitly defers the mitigation (SQL Parameters, SQL Prepared Statements) rather than covering it here. [S1]

📖 세부 내용 (Details)

• Vulnerable pattern: txtUserId = getRequestString("UserId"); txtSQL = "SELECT * FROM Users WHERE UserId = " + txtUserId;. [S1]
• Tautology exploit: input 105 OR 1=1 yields SELECT * FROM Users WHERE UserId = 105 OR 1=1;, returning ALL rows. [S1]
• Login bypass exploit: input " OR ""=" on both fields yields SELECT * FROM Users WHERE Name ="" or ""="" AND Pass ="" or ""="", which is always true. [S1]
• Batched destructive exploit: SELECT * FROM Users WHERE UserId = 105; DROP TABLE Suppliers;. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 다음 두 챕터(SQL Parameters, SQL Prepared Statements)가 이 문제의 실제 해결책을 제시한다. [S1]

💻 코드 패턴 (Code patterns)

Vulnerable string-concatenation pattern (illustrative, NOT recommended):

txtUserId = getRequestString("UserId");
txtSQL = "SELECT * FROM Users WHERE UserId = " + txtUserId;

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.87
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: SQL Tutorial
• 관련 개념: SQL Parameters, SQL Prepared Statements
• 참조 맥락: 사용자 입력을 다루는 모든 쿼리 작성 전 반드시 인지해야 할 보안 위협 — 해결책은 다음 두 챕터.

📚 출처 (Sources)

• [S1] W3Schools — SQL Injection — https://www.w3schools.com/sql/sql_injection.asp

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "SQL Injection" page (Astra wiki-curation, P-Reinforce v3.1 format).