MEDIUM CVSS 4.5
Published: 2021-01-13

CVE-2020-36191

jupyter jupyterhub Security Advisory (CVE-2020-36191)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-36191 impacting jupyter jupyterhub. Evaluated with CVSS Base Score of 4.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
JupyterHub 1.1.0 allows CSRF in the admin panel via a request that lacks an _xsrf field, as demonstrated by a /hub/api/user request (to add or remove a user account).

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
High (PR:H)
Administrative credentials required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product jupyter / jupyterhub
Affected Versions 1.1.0
Weakness Enumeration CWE-352

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2020-36191 impacting jupyter jupyterhub.

⚡ Nuclei Detection Template (YAML) cve-2020-36191.yaml
id: cve-2020-36191

info:
  name: jupyter jupyterhub - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2020-36191 affecting jupyter jupyterhub.
    Evaluation: JupyterHub 1.1.0 allows CSRF in the admin panel via a request that lacks an _xsrf field, as demonstrated by a /hub/api/user request (to add or remove ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-36191
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N
    cvss-score: 4.5
    cve-id: CVE-2020-36191
    cwe-id: CWE-352
  tags: cve,cve-2020-36191,jupyter,jupyterhub,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "jupyterhub"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-36191.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-36191
# Target: jupyter jupyterhub | CVSS: 4.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-36191 (jupyter jupyterhub)...")
    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 jupyter jupyterhub scope (1.1.0).")
        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)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2020-36191.sh
# Recommended Remediation & Patching Commands for CVE-2020-36191
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install jupyterhub 2>/dev/null || \
sudo dnf upgrade jupyterhub 2>/dev/null || \
sudo yum update jupyterhub

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i jupyterhub 2>/dev/null || rpm -qa | grep -i jupyterhub

# 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.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2020-36191 in jupyter jupyterhub?

Review vendor-specific security notices and update jupyter jupyterhub 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-2020-36191?

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-2020-36191?

CVE-2020-36191 is classified with a CVSS 3.1 Base Score of 4.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.5
MEDIUM SEVERITY
CVE ID CVE-2020-36191
Weakness CWE-352
Vendor jupyter
Product jupyterhub
Published 2021-01-13
Vector CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N