CVE-2021-26073
CyberVault Technical Summary
Analyst SynthesisTechnical analysis, exploit verification, and patch instructions for CVE-2021-26073 impacting atlassian connect_express. Evaluated with CVSS Base Score of 7.7 (HIGH).
Original NVD Description
Source: NIST NVD📊 CVSS v3.1 Metric Breakdown
🎯 Affected Versions Matrix
| Affected Product | atlassian / connect_express |
| Affected Versions | * |
| Weakness Enumeration | CWE-287 |
Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe
Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2021-26073 impacting atlassian connect_express.
id: cve-2021-26073
info:
name: atlassian connect_express - Security Advisory & Vulnerability Scan
author: cybervault-security-intel
severity: high
description: |
Automated signature & scanner for CVE-2021-26073 affecting atlassian connect_express.
Evaluation: Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for b...
reference:
- https://cybervault-cve.pages.dev/cve/CVE-2021-26073
classification:
cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
cvss-score: 7.7
cve-id: CVE-2021-26073
cwe-id: CWE-287
tags: cve,cve-2021-26073,atlassian,connect_express,high
http:
- method: GET
path:
- "{BaseURL}/"
- "{BaseURL}/api/"
matchers-condition: and
matchers:
- type: status
status:
- 200
- type: word
words:
- "connect_express"
part: body
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-26073
# Target: atlassian connect_express | CVSS: 7.7 (HIGH)
# Educational & Security Audit Purpose Only
import requests
import sys
def verify_vulnerability(target_url):
print(f"[*] Auditing {target_url} for CVE-2021-26073 (atlassian connect_express)...")
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 atlassian connect_express 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-2021-26073
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install connect_express 2>/dev/null || \
sudo dnf upgrade connect_express 2>/dev/null || \
sudo yum update connect_express
# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i connect_express 2>/dev/null || rpm -qa | grep -i connect_express
# 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.
- No records filed in this category.
- ↗ https://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-a%5B%E2%80%A6%5Dypass-of-app-qsh-verification-via-context-jwts/47072
- ↗ https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986099
- ↗ https://security.netapp.com/advisory/ntap-20210604-0004/
- ↗ https://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-a%5B%E2%80%A6%5Dypass-of-app-qsh-verification-via-context-jwts/47072
- ↗ https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986099
❓ Frequently Asked Questions (FAQ) & Remediation Guide
How do I fix CVE-2021-26073 in atlassian connect_express?
Review vendor-specific security notices and update atlassian connect_express 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-2021-26073?
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-2021-26073?
CVE-2021-26073 is classified with a CVSS 3.1 Base Score of 7.7 (HIGH). Check the metric breakdown above for attack vector requirements.