Listen to this Post
How the CVE Works:
CVE-2021-22931 is a critical vulnerability in Node.js that allows remote attackers to execute arbitrary code due to improper input validation in the `http2` module. The flaw arises when handling large HTTP/2 headers, leading to a heap-based buffer overflow. An attacker can exploit this by sending a maliciously crafted HTTP/2 request, triggering memory corruption and potentially gaining control of the application. The vulnerability affects Node.js versions 12.x, 14.x, and 16.x before patches were released.
DailyCVE Form:
Platform: Node.js
Version: 12.x – 16.x
Vulnerability: HTTP/2 RCE
Severity: Critical
Date: 2021-09-01
Prediction: Patch expected 2021-09-15
What Undercode Say:
Exploitation:
1. Craft malicious HTTP/2 request with oversized headers.
2. Target Node.js servers with unpatched versions.
3. Trigger buffer overflow for RCE.
Protection:
1. Update Node.js to v12.22.6, v14.17.6, or v16.6.2.
2. Disable HTTP/2 if unused via `–disable-http2`.
3. Implement WAF rules to block oversized headers.
Detection Commands:
node -v Check Node.js version grep -r "http2" /etc/node Verify HTTP/2 usage
Mitigation Script:
const http2 = require('http2');
const server = http2.createSecureServer({
maxHeaderSize: 8192 // Enforce header size limit
});
Log Analysis:
cat /var/log/node.log | grep "HTTP/2" | grep "oversize"
Exploit POC (For Research):
import socket target = "victim.com" payload = "A" 10000 Malformed headers send_http2(target, payload)
Patch Verification:
npm audit --production Check for vulnerabilities
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
