HIGH CVSS 8.5
Published: 2025-06-16

CVE-2025-5689

canonical authd Security Advisory (CVE-2025-5689)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-5689 impacting canonical authd. Evaluated with CVSS Base Score of 8.5 (HIGH).

Original NVD Description

Source: NIST NVD
A flaw was found in the temporary user record that authd uses in the pre-auth NSS. As a result, a user login for the first time will be considered to be part of the root group in the context of that SSH session.

📊 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
Low (PR:L)
Standard user access required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product canonical / authd
Affected Versions *
Weakness Enumeration CWE-269

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-2025-5689 impacting canonical authd.

⚡ Nuclei Detection Template (YAML) cve-2025-5689.yaml
id: cve-2025-5689

info:
  name: canonical authd - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2025-5689 affecting canonical authd.
    Evaluation: A flaw was found in the temporary user record that authd uses in the pre-auth NSS. As a result, a user login for the first time will be considered to ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-5689
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
    cvss-score: 8.5
    cve-id: CVE-2025-5689
    cwe-id: CWE-269
  tags: cve,cve-2025-5689,canonical,authd,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "authd"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-5689.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-5689
# Target: canonical authd | CVSS: 8.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-5689 (canonical authd)...")
    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 canonical authd 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-2025-5689.sh
# Recommended Remediation & Patching Commands for CVE-2025-5689
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install authd 2>/dev/null || \
sudo dnf upgrade authd 2>/dev/null || \
sudo yum update authd

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

# 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

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2025-5689 in canonical authd?

Review vendor-specific security notices and update canonical authd 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-2025-5689?

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-2025-5689?

CVE-2025-5689 is classified with a CVSS 3.1 Base Score of 8.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.5
HIGH SEVERITY
CVE ID CVE-2025-5689
Weakness CWE-269
Vendor canonical
Product authd
Published 2025-06-16
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N