Cross-site Scripting (XSS) in navigateTo if used after SSR in nuxt

published 2024-08-05 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-2661 , GHSA-vf6r-87q4-2vjf

cvss: 6.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits: 0; none known

Nuxt is a free and open-source framework to create full-stack web applications and websites with Vue.js. 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. 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. This ONLY has impact after SSR has occured, the `javascript:` protocol within a location header does not trigger XSS. This issue has been addressed in release version 3.12.4 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

fixed in 2

npm nuxt 3.12.4
nuxt nuxt 3.12.4

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-08-08)

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/nuxt/nuxt/security/advisories/GHSA-vf6r-87q4-2vjf referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
GitHub	3.1	6.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	nuxt	<3.12.4	3.12.4

Affected products

nuxt nuxt

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-83 Improper Neutralization of Script in Attributes in a Web Page

References

github.com /nuxt/nuxt/security/advisories/GHSA-vf6r-87q4-2vjf
web, exploit, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2024-34343
advisory
github.com /nuxt/nuxt
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary