GHSA-VF6R-87Q4-2VJF
Vulnerability from github – Published: 2024-08-05 19:49 – Updated: 2025-05-15 21:26Summary
The navigateTo function attempts to blockthe javascript: protocol, but does not correctly use API's provided by unjs/ufo. This library also contains parsing discrepancies.
Details
The function first tests to see if the specified URL has a protocol. This uses the unjs/ufo package for URL parsing. This function works effectively, and returns true for a javascript: protocol.
After this, the URL is parsed using the parseURL function. This function will refuse to parse poorly formatted URLs. Parsing javascript:alert(1) returns null/"" for all values.
Next, the protocol of the URL is then checked using the isScriptProtocol function. This function simply checks the input against a list of protocols, and does not perform any parsing.
The combination of refusing to parse poorly formatted URLs, and not performing additional parsing means that script checks fail as no protocol can be found. Even if a protocol was identified, whitespace is not stripped in the parseURL implementation, bypassing the isScriptProtocol checks.
Certain special protocols are identified at the top of parseURL. Inserting a newline or tab into this sequence will block the special protocol check, and bypass the latter checks.
PoC
POC - https://stackblitz.com/edit/nuxt-xss-navigateto?file=app.vue
Attempt payload X, then attempt payload Y.
Impact
XSS, access to cookies, make requests on user's behalf.
Recommendations
As always with these bugs, the URL constructor provided by the browser is always the safest method of parsing a URL.
Given the cross-platform requirements of nuxt/ufo a more appropriate solution is to make parsing consistent between functions, and to adapt parsing to be more consistent with the WHATWG URL specification.
Note
I've reported this vulnerability here as it is unclear if this is a bug in ufo or a misuse of the ufo library.
This ONLY has impact after SSR has occurred, the javascript: protocol within a location header does not trigger XSS.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "nuxt"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.12.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-34343"
],
"database_specific": {
"cwe_ids": [
"CWE-79",
"CWE-83"
],
"github_reviewed": true,
"github_reviewed_at": "2024-08-05T19:49:22Z",
"nvd_published_at": "2024-08-05T21:15:38Z",
"severity": "MODERATE"
},
"details": "### Summary\nThe `navigateTo` function attempts to blockthe `javascript:` protocol, but does not correctly use API\u0027s provided by `unjs/ufo`. This library also contains parsing discrepancies.\n\n### Details\nThe function first tests to see if the specified [URL has a protocol](https://github.com/nuxt/nuxt/blob/fa9d43753d25fc2e8c3107f194b2bab6d4ebcb9a/packages/nuxt/src/app/composables/router.ts#L142). This uses the [unjs/ufo](https://github.com/unjs/ufo) package for URL parsing. This function works effectively, and returns true for a `javascript:` protocol.\n\nAfter this, the URL is parsed using the [`parseURL`](https://github.com/unjs/ufo/blob/e970686b2acae972136f478732450f6a2f1ab5e5/src/parse.ts#L47) function. This function will refuse to parse poorly formatted URLs. Parsing `javascript:alert(1)` returns null/\"\" for all values. \n\nNext, the protocol of the URL is then checked using the [`isScriptProtocol`](https://github.com/unjs/ufo/blob/e970686b2acae972136f478732450f6a2f1ab5e5/src/utils.ts#L74) function. This function simply checks the input against a list of protocols, and does not perform any parsing. \n\nThe combination of refusing to parse poorly formatted URLs, and not performing additional parsing means that script checks fail as no protocol can be found. Even if a protocol was identified, whitespace is not stripped in the `parseURL` implementation, bypassing the `isScriptProtocol` checks. \n\nCertain special protocols are identified at the top of [`parseURL`](https://github.com/unjs/ufo/blob/e970686b2acae972136f478732450f6a2f1ab5e5/src/parse.ts#L49). Inserting a newline or tab into this sequence will block the special protocol check, and bypass the latter checks. \n\n### PoC\nPOC - https://stackblitz.com/edit/nuxt-xss-navigateto?file=app.vue\n\nAttempt payload X, then attempt payload Y.\n\n### Impact\nXSS, access to cookies, make requests on user\u0027s behalf. \n\n### Recommendations\nAs always with these bugs, the `URL` constructor provided by the browser is always the safest method of parsing a URL. \n\nGiven the cross-platform requirements of nuxt/ufo a more appropriate solution is to make parsing consistent between functions, and to adapt parsing to be more consistent with the [WHATWG URL specification](https://url.spec.whatwg.org/).\n\n### Note\nI\u0027ve reported this vulnerability here as it is unclear if this is a bug in ufo or a misuse of the ufo library.\n\nThis ONLY has impact after SSR has occurred, the `javascript:` protocol within a location header does not trigger XSS.",
"id": "GHSA-vf6r-87q4-2vjf",
"modified": "2025-05-15T21:26:45Z",
"published": "2024-08-05T19:49:22Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/nuxt/nuxt/security/advisories/GHSA-vf6r-87q4-2vjf"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-34343"
},
{
"type": "PACKAGE",
"url": "https://github.com/nuxt/nuxt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "nuxt vulnerable to Cross-site Scripting in navigateTo if used after SSR"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.