MEDIUM CVSS 6.7
Published: 2025-03-12

CVE-2025-20177

cisco ios_xr Security Advisory (CVE-2025-20177)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-20177 impacting cisco ios_xr. Evaluated with CVSS Base Score of 6.7 (MEDIUM).

Original NVD Description

Source: NIST NVD
A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR image signature verification and load unverified software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device. This vulnerability is due to incomplete validation of files in the boot verification process. An attacker could exploit this vulnerability by manipulating the system configuration options to bypass some of the integrity checks that are performed during the boot process. A successful exploit could allow the attacker to control the boot configuration, which could enable them to bypass the requirement to run Cisco-signed images or alter the security properties of the running system. Note: Because exploitation of this vulnerability could result in the attacker bypassing Cisco image verification, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.

📊 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
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product cisco / ios_xr
Affected Versions *
Weakness Enumeration CWE-274

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-2025-20177 impacting cisco ios_xr.

⚡ Nuclei Detection Template (YAML) cve-2025-20177.yaml
id: cve-2025-20177

info:
  name: cisco ios_xr - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2025-20177 affecting cisco ios_xr.
    Evaluation: A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR image signature verif...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-20177
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 6.7
    cve-id: CVE-2025-20177
    cwe-id: CWE-274
  tags: cve,cve-2025-20177,cisco,ios_xr,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "ios_xr"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-20177.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-20177
# Target: cisco ios_xr | CVSS: 6.7 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-20177 (cisco ios_xr)...")
    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 cisco ios_xr 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-2025-20177.sh
# Recommended Remediation & Patching Commands for CVE-2025-20177
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install ios_xr 2>/dev/null || \
sudo dnf upgrade ios_xr 2>/dev/null || \
sudo yum update ios_xr

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

# 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-2025-20177 in cisco ios_xr?

Review vendor-specific security notices and update cisco ios_xr 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-2025-20177?

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-2025-20177?

CVE-2025-20177 is classified with a CVSS 3.1 Base Score of 6.7 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.7
MEDIUM SEVERITY
CVE ID CVE-2025-20177
Weakness CWE-274
Vendor cisco
Product ios_xr
Published 2025-03-12
Vector CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H