CVE-2018-3771 — statics-server
MEDIUMCVE-2018-3771 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in statics-server. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
statics-server Cross-site Scripting vulnerability
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
statics-servernpmDescription
An XSS in statics-server <= 0.0.9 can be used via injected iframe in the filename when statics-server displays directory index in the browser. Statics-server does not implement any HTML escaping when displays directory index in the browser. Variable v is used in <a href> element without escaping, which allows to embed HTML <iframe> tag with src attribute points to another HTML file in the directory. This file can contain malicious JavaScript code, which will be executed:
// ./node_modules/statics-server/index.js, line 18:
if(fs.lstatSync(staticPath).isDirectory()){
var files=fs.readdirSync(staticPath);
var lis='';
files.forEach((v,i)=>{
if(fs.lstatSync(path.resolve(staticPath,v)).isDirectory()){
lis+=`<li><a href="${req.url}${v}/">${v}/</a></li>`;
}else {
lis+=`<li><a href="${req.url}${v}">${v}</a></li>`
}
});
(...)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | statics-server | all versions | No fix |
Affected Products
statics-serverstatics-server_projectResearch 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 statics-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of statics-server for CVE-2018-3771. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2018-3771 in your dependencies?
Find it across npm, including transitive dependencies.