{"id":"GHSA-3wgp-x9p5-c7cc","summary":"Appium: Reflected XSS / arbitrary JS in @appium/base-driver /test/guinea-pig* routes","details":"## Summary\n\nAppium's base-driver mounts the built-in `/test/guinea-pig`, `/test/guinea-pig-scrollable` and `/test/guinea-pig-app-banner` routes **unconditionally** on every server. The handler reflects the `throwError` query param, the `comments` POST field, and the `User-Agent` request header into the returned HTML via `compileLodashTemplate`, which interpolates `\u003c%= expr %\u003e` as `String(expr)` with **no HTML/JS escaping**. This yields reflected XSS, and the `throwError` value is reflected **inside a `\u003cscript\u003e` block**, giving arbitrary JavaScript execution on the server's origin. No authentication, no session, no driver and no plugin are required, and the default bind address is `0.0.0.0`.\n\n## Details\n\n### Affected\n- `@appium/base-driver` **10.6.0** (with Appium server **3.5.0**); tested live.\n- Template engine helper: `@appium/base-driver` `lib/utils.ts` `compileLodashTemplate`.\n\n### Location (file:line)\n- Routes mounted unconditionally: `base-driver/lib/express/server.ts:216-219`\n(`app.all('/test/guinea-pig', guineaPig)` etc.).\n- Tainting: `base-driver/lib/express/static.ts:35-61` (`guineaPigTemplate`) —\n`throwError = String(req.params.throwError ?? req.query?.throwError)`, `params.comment = String(req.body.comments)`, `params.userAgent = req.headers['user-agent']`.\n- Unescaped render: `base-driver/lib/utils.ts:67-83` (`compileLodashTemplate`)\nemits `\u003c%= expr %\u003e` as `String(${expr})` via `new Function(...)`, no escaping.\n- Sinks (shipped templates): `base-driver/static/test/guinea-pig.html:11-12`\n(`throwError` inside `\u003cscript\u003e`), `:50` (`comment`), `:87` (`userAgent`); same in `guinea-pig-scrollable.html` / `guinea-pig-app-banner.html`.\n\n\n### PoC\n\nRequests:\n```\nGET /test/guinea-pig?throwError=x%27%2balert(document.domain)%2b%27\nPOST /test/guinea-pig         (body: comments=\u003c/span\u003e\u003cimg src=x onerror=alert(1)\u003e)\nGET  /test/guinea-pig         (header: User-Agent: \u003cscript\u003ealert(7)\u003c/script\u003e)\n```\n\n\u003cimg width=\"973\" height=\"276\" alt=\"image\" src=\"https://github.com/user-attachments/assets/f58e1dce-f3ad-43d3-b66e-1ff5efea3866\" /\u003e\n\n\n### Impact\n\nAn attacker who can get a victim to open a crafted link (or auto-submit a form) to the Appium server executes arbitrary JavaScript on the server's origin. With default CORS `*` + no authentication, that JS can drive the WebDriver REST API and plugin endpoints. The endpoints are debug/test fixtures that should not be reachable on a production listener at all.","aliases":["CVE-2026-58191"],"modified":"2026-09-01T19:02:52.961400660Z","published":"2026-09-01T18:54:53Z","database_specific":{"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-09-01T18:54:53Z","nvd_published_at":"2026-07-08T21:16:52Z","cwe_ids":["CWE-489","CWE-79"]},"references":[{"type":"WEB","url":"https://github.com/appium/appium/security/advisories/GHSA-3wgp-x9p5-c7cc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58191"},{"type":"WEB","url":"https://github.com/appium/appium/pull/22394"},{"type":"WEB","url":"https://github.com/appium/appium/commit/d94a40af9f8040191ee7888571a1c9d5aec59f89"},{"type":"PACKAGE","url":"https://github.com/appium/appium"},{"type":"WEB","url":"https://github.com/appium/appium/releases/tag/@appium/base-driver@10.7.0"}],"affected":[{"package":{"name":"@appium/base-driver","ecosystem":"npm","purl":"pkg:npm/%40appium/base-driver"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"10.7.0"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 10.6.0","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-3wgp-x9p5-c7cc/GHSA-3wgp-x9p5-c7cc.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N"}]}