fix(security): P0 — CSRF 방어, h2-console prod 격리, CORS 외부화

- CSRF: CookieCsrfTokenRepository(이중제출 토큰) + SPA용 CsrfTokenRequestAttributeHandler,
  CsrfCookieFilter로 XSRF-TOKEN 쿠키 강제 렌더. /api/auth/login·/api/public/** 는 예외.
  프론트 api.ts가 변경요청에 X-XSRF-TOKEN 헤더 자동 주입.
- 세션쿠키 SameSite=Lax·HttpOnly, prod는 Secure=${ACS_COOKIE_SECURE:false}(HTTPS 시 활성).
- h2-console permitAll·frameOptions.sameOrigin을 spring.h2.console.enabled에 연동 → prod 자동 비노출.
- CORS allowed-origins를 acs.cors.allowed-origins 프로퍼티로 외부화(prod 기본 빈 값, nginx 동일출처).
- .env.example·docker-compose에 ACS_CORS_ALLOWED_ORIGINS·ACS_COOKIE_SECURE 추가.

검증: 빌드/테스트 통과, curl로 CSRF 차단(403)·토큰 통과(404)·로그인/공개 예외·dev h2-console 확인.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/main/java/com/itcenter/acs/config/CsrfCookieFilter.java

@@ -0,0 +1,32 @@
+package com.itcenter.acs.config;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.springframework.security.web.csrf.CsrfToken;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import java.io.IOException;
+
+/**
+ * Forces the {@code XSRF-TOKEN} cookie to be rendered on responses.
+ * <p>
+ * {@link org.springframework.security.web.csrf.CookieCsrfTokenRepository} only writes
+ * the cookie when the token is actually resolved. Calling {@link CsrfToken#getToken()}
+ * here guarantees the SPA receives the cookie (e.g. on the initial {@code GET /api/auth/me}
+ * probe or a public pass page load) so it can echo it back in the {@code X-XSRF-TOKEN} header.
+ */
+public class CsrfCookieFilter extends OncePerRequestFilter {
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
+                                    FilterChain filterChain) throws ServletException, IOException {
+        CsrfToken csrfToken = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
+        if (csrfToken != null) {
+            // Resolving the token value triggers CookieCsrfTokenRepository to set the cookie.
+            csrfToken.getToken();
+        }
+        filterChain.doFilter(request, response);
+    }
+}

backend/src/main/java/com/itcenter/acs/config/SecurityConfig.java

@@ -3,19 +3,22 @@ package com.itcenter.acs.config;
 import com.itcenter.acs.dto.ApiResponse;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import jakarta.servlet.http.HttpServletResponse;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.MediaType;
 import org.springframework.security.authentication.AuthenticationManager;
 import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
-import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
 import org.springframework.security.config.http.SessionCreationPolicy;
 import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;
 import org.springframework.security.web.context.HttpSessionSecurityContextRepository;
 import org.springframework.security.web.context.SecurityContextRepository;
+import org.springframework.security.web.csrf.CookieCsrfTokenRepository;
+import org.springframework.security.web.csrf.CsrfTokenRequestAttributeHandler;
 import org.springframework.web.cors.CorsConfiguration;
 import org.springframework.web.cors.CorsConfigurationSource;
 import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
@@ -31,6 +34,14 @@ public class SecurityConfig {
 
     private final ObjectMapper objectMapper = new ObjectMapper();
 
+    /** Only expose the H2 console (and relax frame options for it) when it is actually enabled — dev only. */
+    @Value("${spring.h2.console.enabled:false}")
+    private boolean h2ConsoleEnabled;
+
+    /** Allowed CORS origins; empty in prod (nginx same-origin), localhost in dev. */
+    @Value("${acs.cors.allowed-origins:http://localhost:5173,http://127.0.0.1:5173}")
+    private List<String> allowedOrigins;
+
     @Bean
     public PasswordEncoder passwordEncoder() {
         return new BCryptPasswordEncoder();
@@ -48,14 +59,33 @@ public class SecurityConfig {
 
     @Bean
     public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
+        // SPA double-submit: the SPA reads the XSRF-TOKEN cookie and echoes it in the
+        // X-XSRF-TOKEN header. The plain handler (XOR opt-out) makes the header value
+        // match the raw cookie token.
+        CsrfTokenRequestAttributeHandler csrfHandler = new CsrfTokenRequestAttributeHandler();
+        csrfHandler.setCsrfRequestAttributeName(null);
+
         http
                 .cors(cors -> {})
-                .csrf(AbstractHttpConfigurer::disable)
-                .authorizeHttpRequests(authz -> authz
+                .csrf(csrf -> csrf
+                        .csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse())
+                        .csrfTokenRequestHandler(csrfHandler)
+                        // login happens before a session exists; public pass endpoints are
+                        // guarded by an unguessable token — both are exempt from CSRF.
+                        .ignoringRequestMatchers("/api/auth/login", "/api/public/**")
+                )
+                // ensure the XSRF-TOKEN cookie is written on every response
+                .addFilterAfter(new CsrfCookieFilter(), BasicAuthenticationFilter.class)
+                .authorizeHttpRequests(authz -> {
+                        authz
                                 // public
                                 .requestMatchers("/api/auth/login", "/api/auth/logout").permitAll()
-                        .requestMatchers("/", "/health", "/error").permitAll()
-                        .requestMatchers("/h2-console/**").permitAll()
+                                .requestMatchers("/", "/health", "/error").permitAll();
+                        // H2 console — dev only (see h2ConsoleEnabled)
+                        if (h2ConsoleEnabled) {
+                                authz.requestMatchers("/h2-console/**").permitAll();
+                        }
+                        authz
                                 // public visitor pass (opened from the SMS link, token-guarded)
                                 .requestMatchers("/api/public/**").permitAll()
                                 // staff access console (search + force check-in/out) — 담당자(HOST)/보안/관리자
@@ -67,10 +97,14 @@ public class SecurityConfig {
                                 // reports — security & admin
                                 .requestMatchers("/api/reports/**").hasAnyRole("SECURITY", "ADMIN")
                                 // everything else requires a logged-in user
-                        .anyRequest().authenticated()
-                )
-                // H2 console renders in a frame
-                .headers(h -> h.frameOptions(f -> f.sameOrigin()))
+                                .anyRequest().authenticated();
+                })
+                // relax frame options only for the H2 console (dev); prod keeps the default DENY
+                .headers(h -> {
+                        if (h2ConsoleEnabled) {
+                                h.frameOptions(f -> f.sameOrigin());
+                        }
+                })
                 .sessionManagement(s -> s.sessionCreationPolicy(SessionCreationPolicy.IF_REQUIRED))
                 .securityContext(sc -> sc.securityContextRepository(securityContextRepository()))
                 .exceptionHandling(ex -> ex
@@ -91,10 +125,8 @@ public class SecurityConfig {
     @Bean
     public CorsConfigurationSource corsConfigurationSource() {
         CorsConfiguration configuration = new CorsConfiguration();
-        configuration.setAllowedOrigins(List.of(
-                "http://localhost:5173",
-                "http://127.0.0.1:5173"
-        ));
+        // allowCredentials=true forbids "*" — origins must be listed explicitly (acs.cors.allowed-origins).
+        configuration.setAllowedOrigins(allowedOrigins);
         configuration.setAllowedMethods(List.of("GET", "POST", "PUT", "DELETE", "OPTIONS"));
         configuration.setAllowedHeaders(List.of("*"));
         configuration.setAllowCredentials(true);

backend/src/main/resources/application-prod.properties

@@ -1,6 +1,19 @@
 spring.application.name=acs
 server.port=8080
 
+# ===== Session cookie hardening =====
+# SameSite=Lax complements the CSRF token defense.
+# Secure=true means the cookie is only sent over HTTPS — enable it (ACS_COOKIE_SECURE=true)
+# ONCE the site is served over HTTPS, otherwise login breaks over plain http://internal-ip.
+server.servlet.session.cookie.same-site=lax
+server.servlet.session.cookie.http-only=true
+server.servlet.session.cookie.secure=${ACS_COOKIE_SECURE:false}
+
+# ===== CORS =====
+# nginx serves web+API from the same origin, so CORS is normally not exercised (empty is fine).
+# Set ACS_CORS_ALLOWED_ORIGINS (comma-separated) only if the SPA is hosted on a different origin.
+acs.cors.allowed-origins=${ACS_CORS_ALLOWED_ORIGINS:}
+
 # ===== PostgreSQL (prod) =====
 spring.datasource.url=jdbc:postgresql://${POSTGRES_HOST:localhost}:${POSTGRES_PORT:5432}/${POSTGRES_DB:acs}
 spring.datasource.driver-class-name=org.postgresql.Driver

backend/src/main/resources/application.properties

@@ -1,6 +1,11 @@
 spring.application.name=acs
 server.port=8080
 
+# ===== Session cookie hardening =====
+# SameSite=Lax complements the CSRF token defense. Secure=false in dev (plain http).
+server.servlet.session.cookie.same-site=lax
+server.servlet.session.cookie.http-only=true
+
 # ===== Logging =====
 logging.level.root=INFO
 logging.level.com.itcenter.acs=DEBUG

frontend/src/api.ts

@@ -21,10 +21,22 @@ const BASE = '/api';
 /** Endpoints whose 401 must NOT trigger a redirect (login probe / public pages). */
 const NO_REDIRECT_ON_401 = ['/auth/me', '/auth/login', '/auth/logout', '/public/'];
 
+/**
+ * CSRF double-submit: the backend sets an XSRF-TOKEN cookie; echo it back in the
+ * X-XSRF-TOKEN header on state-changing requests. GET/HEAD need no token.
+ */
+function csrfHeaders(method?: string): Record<string, string> {
+  const m = (method ?? 'GET').toUpperCase();
+  if (m === 'GET' || m === 'HEAD') return {};
+  const c = document.cookie.match(/(?:^|;\s*)XSRF-TOKEN=([^;]+)/);
+  return c ? { 'X-XSRF-TOKEN': decodeURIComponent(c[1]) } : {};
+}
+
 async function request<T>(path: string, init?: RequestInit): Promise<T> {
   const res = await fetch(`${BASE}${path}`, {
     credentials: 'include',
     ...init,
+    headers: { ...(init?.headers ?? {}), ...csrfHeaders(init?.method) },
   });
   // Session expired / not authenticated on a protected call → send to login.
   if (

infra/.env.example

@@ -16,3 +16,11 @@ ACS_SMS_API_URL=http://210.104.132.59:8000
 # URL the SMS link points to — MUST be reachable from the visitor's phone
 # (the server's real address/domain, not localhost). e.g. https://acs.example.co.kr
 ACS_PUBLIC_BASE_URL=http://localhost
+
+# ===== Security =====
+# CORS allowed origins (comma-separated). Leave EMPTY when web+API share one origin
+# via nginx (default). Set only if the SPA is hosted on a different origin.
+ACS_CORS_ALLOWED_ORIGINS=
+# Set to true ONLY when the site is served over HTTPS — marks the session cookie Secure.
+# Leaving it false over plain http keeps login working; true over http would break it.
+ACS_COOKIE_SECURE=false

infra/docker-compose.yml

@@ -28,6 +28,9 @@ services:
       ACS_SMS_PROVIDER: ${ACS_SMS_PROVIDER:-dev}
       ACS_SMS_API_URL: ${ACS_SMS_API_URL:-http://210.104.132.59:8000}
       ACS_PUBLIC_BASE_URL: ${ACS_PUBLIC_BASE_URL:-http://localhost}
+      # Security: CORS origins (empty = same-origin via nginx); cookie Secure (enable under HTTPS)
+      ACS_CORS_ALLOWED_ORIGINS: ${ACS_CORS_ALLOWED_ORIGINS:-}
+      ACS_COOKIE_SECURE: ${ACS_COOKIE_SECURE:-false}
     depends_on:
       - db
     networks: