MEDIUM CVSS 5.8
Published: 2025-07-11

CVE-2025-52951

juniper junos Security Advisory (CVE-2025-52951)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-52951 impacting juniper junos. Evaluated with CVSS Base Score of 5.8 (MEDIUM).

Original NVD Description

Source: NIST NVD
A Protection Mechanism Failure vulnerability in kernel filter processing of Juniper Networks Junos OS allows an attacker sending IPv6 traffic destined to the device to effectively bypass any firewall filtering configured on the interface. Due to an issue with Junos OS kernel filter processing, the 'payload-protocol' match is not being supported, causing any term containing it to accept all packets without taking any other action. In essence, these firewall filter terms were being processed as an 'accept' for all traffic on the interface destined for the control plane, even when used in combination with other match criteria. This issue only affects firewall filters protecting the device's control plane. Transit firewall filtering is unaffected by this vulnerability. This issue affects Junos OS:  * all versions before 21.2R3-S9,  * from 21.4 before 21.4R3-S11,  * from 22.2 before 22.2R3-S7,  * from 22.4 before 22.4R3-S7,  * from 23.2 before 23.2R2-S4,  * from 23.4 before 23.4R2-S5,  * from 24.2 before 24.2R2-S1,  * from 24.4 before 24.4R1-S2, 24.4R2. This is a more complete fix for previously published CVE-2024-21607 (JSA75748).

📊 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
None (PR:N)
Unauthenticated execution
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
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product juniper / junos
Affected Versions *
Weakness Enumeration CWE-693

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-2025-52951 impacting juniper junos.

⚡ Nuclei Detection Template (YAML) cve-2025-52951.yaml
id: cve-2025-52951

info:
  name: juniper junos - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2025-52951 affecting juniper junos.
    Evaluation: A Protection Mechanism Failure vulnerability in kernel filter processing of Juniper Networks Junos OS allows an attacker sending IPv6 traffic destined...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-52951
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
    cvss-score: 5.8
    cve-id: CVE-2025-52951
    cwe-id: CWE-693
  tags: cve,cve-2025-52951,juniper,junos,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "junos"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-52951.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-52951
# Target: juniper junos | CVSS: 5.8 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-52951 (juniper junos)...")
    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 juniper junos 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-2025-52951.sh
# Recommended Remediation & Patching Commands for CVE-2025-52951
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install junos 2>/dev/null || \
sudo dnf upgrade junos 2>/dev/null || \
sudo yum update junos

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

# 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-2025-52951 in juniper junos?

Review vendor-specific security notices and update juniper junos 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-2025-52951?

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-2025-52951?

CVE-2025-52951 is classified with a CVSS 3.1 Base Score of 5.8 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.8
MEDIUM SEVERITY
CVE ID CVE-2025-52951
Weakness CWE-693
Vendor juniper
Product junos
Published 2025-07-11
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N