CVE-2021-27218
CyberVault Technical Summary
Analyst SynthesisTechnical analysis, exploit verification, and patch instructions for CVE-2021-27218 impacting gnome glib. Evaluated with CVSS Base Score of 7.5 (HIGH).
Original NVD Description
Source: NIST NVD📊 CVSS v3.1 Metric Breakdown
🎯 Affected Versions Matrix
| Affected Product | gnome / glib |
| Affected Versions | * |
| Weakness Enumeration | CWE-681 |
Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe
Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2021-27218 impacting gnome glib.
id: cve-2021-27218
info:
name: gnome glib - Security Advisory & Vulnerability Scan
author: cybervault-security-intel
severity: high
description: |
Automated signature & scanner for CVE-2021-27218 affecting gnome glib.
Evaluation: An issue was discovered in GNOME GLib before 2.66.7 and 2.67.x before 2.67.4. If g_byte_array_new_take() was called with a buffer of 4GB or more on a ...
reference:
- https://cybervault-cve.pages.dev/cve/CVE-2021-27218
classification:
cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cvss-score: 7.5
cve-id: CVE-2021-27218
cwe-id: CWE-681
tags: cve,cve-2021-27218,gnome,glib,high
http:
- method: GET
path:
- "{BaseURL}/"
- "{BaseURL}/api/"
matchers-condition: and
matchers:
- type: status
status:
- 200
- type: word
words:
- "glib"
part: body
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-27218
# Target: gnome glib | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only
import requests
import sys
def verify_vulnerability(target_url):
print(f"[*] Auditing {target_url} for CVE-2021-27218 (gnome glib)...")
headers = {
"User-Agent": "CyberVault-Audit-Scanner/2.0",
"Accept": "*/*"
}
try:
r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
if r.status_code < 500:
print(f"[!] Target reachable. Verify version against gnome glib scope (*).")
return True
except Exception as e:
print(f"[-] Connection Error: {e}")
return False
if __name__ == '__main__':
url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
verify_vulnerability(url)
# Recommended Remediation & Patching Commands for CVE-2021-27218
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install glib 2>/dev/null || \
sudo dnf upgrade glib 2>/dev/null || \
sudo yum update glib
# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i glib 2>/dev/null || rpm -qa | grep -i glib
# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."
🛡️ Remediation & Security Action
- Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
- Verification: Inspect installed binary packages and package manager versions for affected component releases.
- Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
🔗 Verified Technical References
- No records filed in this category.
- ↗ https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1942
- ↗ https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1944
- ↗ https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
- ↗ https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- ↗ https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
❓ Frequently Asked Questions (FAQ) & Remediation Guide
How do I fix CVE-2021-27218 in gnome glib?
Review vendor-specific security notices and update gnome glib packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.
Is there an active exploit or public PoC for CVE-2021-27218?
No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.
What is the CVSS 3.1 severity rating and impact for CVE-2021-27218?
CVE-2021-27218 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.