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

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

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 make_spec.py reproduce.sh