MEDIUM CVSS 4.4
Published: 2021-05-10

CVE-2021-25645

couchbase couchbase_server Security Advisory (CVE-2021-25645)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-25645 impacting couchbase couchbase_server. Evaluated with CVSS Base Score of 4.4 (MEDIUM).

Original NVD Description

Source: NIST NVD
An issue was discovered in Couchbase Server before 6.0.5, 6.1.x through 6.5.x before 6.5.2, and 6.6.x before 6.6.1. An internal user with administrator privileges, @ns_server, leaks credentials in cleartext in the cbcollect_info.log, debug.log, ns_couchdb.log, indexer.log, and stats.log files. NOTE: updating the product does not automatically address leaks that occurred in the past.

📊 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
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product couchbase / couchbase_server
Affected Versions *
Weakness Enumeration CWE-312

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-2021-25645 impacting couchbase couchbase_server.

⚡ Nuclei Detection Template (YAML) cve-2021-25645.yaml
id: cve-2021-25645

info:
  name: couchbase couchbase_server - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2021-25645 affecting couchbase couchbase_server.
    Evaluation: An issue was discovered in Couchbase Server before 6.0.5, 6.1.x through 6.5.x before 6.5.2, and 6.6.x before 6.6.1. An internal user with administrato...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-25645
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 4.4
    cve-id: CVE-2021-25645
    cwe-id: CWE-312
  tags: cve,cve-2021-25645,couchbase,couchbase_server,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "couchbase_server"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-25645.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-25645
# Target: couchbase couchbase_server | CVSS: 4.4 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-25645 (couchbase couchbase_server)...")
    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 couchbase couchbase_server 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-2021-25645.sh
# Recommended Remediation & Patching Commands for CVE-2021-25645
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install couchbase_server 2>/dev/null || \
sudo dnf upgrade couchbase_server 2>/dev/null || \
sudo yum update couchbase_server

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

# 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-2021-25645 in couchbase couchbase_server?

Review vendor-specific security notices and update couchbase couchbase_server 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-2021-25645?

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-2021-25645?

CVE-2021-25645 is classified with a CVSS 3.1 Base Score of 4.4 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.4
MEDIUM SEVERITY
CVE ID CVE-2021-25645
Weakness CWE-312
Vendor couchbase
Product couchbase_server
Published 2021-05-10
Vector CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N