MEDIUM CVSS 6.0
Published: 2020-12-15

CVE-2020-29482

xen xen Security Advisory (CVE-2020-29482)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-29482 impacting xen xen. Evaluated with CVSS Base Score of 6.0 (MEDIUM).

Original NVD Description

Source: NIST NVD
An issue was discovered in Xen through 4.14.x. A guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path, which implicitly includes /local/domain/$DOMID for their own domain id. Management tools must access paths in guests' namespaces, necessarily using absolute paths. oxenstored imposes a pathname limit that is applied solely to the relative or absolute path specified by the client. Therefore, a guest can create paths in its own namespace which are too long for management tools to access. Depending on the toolstack in use, a malicious guest administrator might cause some management tools and debugging operations to fail. For example, a guest administrator can cause "xenstore-ls -r" to fail. However, a guest administrator cannot prevent the host administrator from tearing down the domain. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Local (AV:L)
Requires local system execution permissions
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
High (PR:H)
Administrative credentials required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product xen / xen
Affected Versions *
Weakness Enumeration CWE-426

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-2020-29482 impacting xen xen.

⚡ Nuclei Detection Template (YAML) cve-2020-29482.yaml
id: cve-2020-29482

info:
  name: xen xen - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2020-29482 affecting xen xen.
    Evaluation: An issue was discovered in Xen through 4.14.x. A guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-29482
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
    cvss-score: 6.0
    cve-id: CVE-2020-29482
    cwe-id: CWE-426
  tags: cve,cve-2020-29482,xen,xen,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "xen"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-29482.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-29482
# Target: xen xen | CVSS: 6.0 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-29482 (xen xen)...")
    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 xen xen 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)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2020-29482.sh
# Recommended Remediation & Patching Commands for CVE-2020-29482
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install xen 2>/dev/null || \
sudo dnf upgrade xen 2>/dev/null || \
sudo yum update xen

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

# 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.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2020-29482 in xen xen?

Review vendor-specific security notices and update xen xen 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-2020-29482?

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-2020-29482?

CVE-2020-29482 is classified with a CVSS 3.1 Base Score of 6.0 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.0
MEDIUM SEVERITY
CVE ID CVE-2020-29482
Weakness CWE-426
Vendor xen
Product xen
Published 2020-12-15
Vector CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H