Orval: Import-time RCE via schema default -> zod module-level template literal

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, a ${...} expression or backtick in a schema default is emitted into a module-level template literal emitted by zod schema generation without safe encoding. This permits attacker-controlled JavaScript to be evaluated when the generated zod schema module is imported, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/zod/src/index.ts function formatDefaultValue. This issue is fixed in version 8.21.0.

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, a ${...} expression or backtick in a schema default is emitted into a module-level template literal emitted by zod schema generation without safe encoding. This permits attacker-controlled JavaScript to be evaluated when the generated zod schema module is imported, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/zod/src/index.ts function formatDefaultValue. This issue is fixed in version 8.21.0.

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, a ${...} expression or backtick in a schema default is emitted into a module-level template literal emitted by zod schema generation without safe encoding. This permits attacker-controlled JavaScript to be evaluated when the generated zod schema module is imported, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/zod/src/index.ts function formatDefaultValue. This issue is fixed in version 8.21.0.

### Summary Orval's zod schema generation emits a schema's `default` value as a module-level template literal (`export const …Default = `<default>`;`) without escaping `${` or the backtick. A default of the form `v${<code>}w` injects a live JavaScript expression that is evaluated when the generated zod schema module is imported, executing attacker-controlled code at import — no request or function call needed. Verified on Orval 8.19.0; survives default OpenAPI validation. ### Details ```ts export const getIResponseDsDefault = `v${globalThis.ORVPWN()}w`; ``` `${...}` permits an arbitrary JS expression. Orval escapes its other value sinks (enum, mock, regex, object-default values) with `\'` inside single-quoted strings; the string `default` is the one value emitted as a backtick template literal, so `${...}`/backtick are interpreted, not escaped. Distinct from the URL-template-literal cases (different field and sink) and from the published Orval CVEs (summary/MCP, x-enumDescriptions, const/mock). ### PoC `reproduce.sh` (+ `make_spec.py`) attached: generates the zod schema with default validation, bundles it, imports it, and shows a marker written at import. Verified on 8.19.0. ### Impact Code execution at import in any application that imports a zod schema module generated from an attacker-controlled or attacker-influenced OpenAPI description. ### Suggested fix Emit `default` values via a proper string-literal encoder (JSON.stringify, or escape backtick and ${ if a template literal must be used); never interpolate a spec value into a template literal. [maintainer-report.txt](https://github.com/user-attachments/files/29399048/maintainer-report.txt) [make_spec.py](https://github.com/user-attachments/files/29399049/make_spec.py) [reproduce.sh](https://github.com/user-attachments/files/29399050/reproduce.sh)