MEDIUM CVSS 5.3
Published: 2017-04-27

CVE-2017-8301

openbsd libressl Security Advisory (CVE-2017-8301)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2017-8301 impacting openbsd libressl. Evaluated with CVSS Base Score of 5.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
LibreSSL 2.5.1 to 2.5.3 lacks TLS certificate verification if SSL_get_verify_result is relied upon for a later check of a verification result, in a use case where a user-provided verification callback returns 1, as demonstrated by acceptance of invalid certificates by nginx.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product openbsd / libressl
Affected Versions 2.5.1
Weakness Enumeration CWE-295

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-2017-8301 impacting openbsd libressl.

⚡ Nuclei Detection Template (YAML) cve-2017-8301.yaml
id: cve-2017-8301

info:
  name: openbsd libressl - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2017-8301 affecting openbsd libressl.
    Evaluation: LibreSSL 2.5.1 to 2.5.3 lacks TLS certificate verification if SSL_get_verify_result is relied upon for a later check of a verification result, in a us...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2017-8301
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
    cvss-score: 5.3
    cve-id: CVE-2017-8301
    cwe-id: CWE-295
  tags: cve,cve-2017-8301,openbsd,libressl,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "libressl"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2017-8301.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2017-8301
# Target: openbsd libressl | CVSS: 5.3 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2017-8301 (openbsd libressl)...")
    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 openbsd libressl scope (2.5.1).")
        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-2017-8301.sh
# Recommended Remediation & Patching Commands for CVE-2017-8301
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install libressl 2>/dev/null || \
sudo dnf upgrade libressl 2>/dev/null || \
sudo yum update libressl

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

# 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-2017-8301 in openbsd libressl?

Review vendor-specific security notices and update openbsd libressl 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-2017-8301?

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-2017-8301?

CVE-2017-8301 is classified with a CVSS 3.1 Base Score of 5.3 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.3
MEDIUM SEVERITY
CVE ID CVE-2017-8301
Weakness CWE-295
Vendor openbsd
Product libressl
Published 2017-04-27
Vector CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N