LOW CVSS 3.9
Published: 2026-03-30

CVE-2025-66038

opensc_project opensc Security Advisory (CVE-2025-66038)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-66038 impacting opensc_project opensc. Evaluated with CVSS Base Score of 3.9 (LOW).

Original NVD Description

Source: NIST NVD
OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Physical (AV:P)
Requires physical access to target hardware
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product opensc_project / opensc
Affected Versions *
Weakness Enumeration CWE-126

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-2025-66038 impacting opensc_project opensc.

⚡ Nuclei Detection Template (YAML) cve-2025-66038.yaml
id: cve-2025-66038

info:
  name: opensc_project opensc - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: low
  description: |
    Automated signature & scanner for CVE-2025-66038 affecting opensc_project opensc.
    Evaluation: OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given ta...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-66038
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
    cvss-score: 3.9
    cve-id: CVE-2025-66038
    cwe-id: CWE-126
  tags: cve,cve-2025-66038,opensc_project,opensc,low

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "opensc"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-66038.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-66038
# Target: opensc_project opensc | CVSS: 3.9 (LOW)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-66038 (opensc_project opensc)...")
    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 opensc_project opensc 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-2025-66038.sh
# Recommended Remediation & Patching Commands for CVE-2025-66038
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install opensc 2>/dev/null || \
sudo dnf upgrade opensc 2>/dev/null || \
sudo yum update opensc

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

# 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-2025-66038 in opensc_project opensc?

Review vendor-specific security notices and update opensc_project opensc 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-2025-66038?

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-2025-66038?

CVE-2025-66038 is classified with a CVSS 3.1 Base Score of 3.9 (LOW). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
3.9
LOW SEVERITY
CVE ID CVE-2025-66038
Weakness CWE-126
Vendor opensc_project
Product opensc
Published 2026-03-30
Vector CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L