CVE-2024-34343
MEDIUMCross-site Scripting (XSS) in navigateTo if used after SSR in nuxt
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
nuxtReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | nuxt | all versions | 3.12.4 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nuxt. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update nuxt to 3.12.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-34343 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2024-34343 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2024-34343. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-34343 in your dependencies?
O3 detects CVE-2024-34343 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.