CVE-2025-20265 Exploit Metadata

PoC files

6 files

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Analysisdeepseek-v4-pro:cloud · 2026-08-12

Technical assessment

A bash script (exploit.sh) that sends a crafted JSON payload to a simulated Cisco FMC server, causing it to execute an arbitrary shell command. The README explicitly states it demonstrates the impact class of CVE-2025-20265.

Backdoor review

No backdoor observed in reviewed code

The reviewed text files (Dockerfile, README.md, exploit.sh) describe and implement a local educational simulation of a Cisco FMC management-plane RCE. The exploit.sh script sends a user-supplied command to a local server, and the README explicitly states the simulation is for local learning only. No concealed, deceptive, or operator-directed harmful behavior (credential theft, unrelated remote access, persistence) is present in the supplied evidence.

ClassificationExploit

Model confidence95%

AuthenticationNot required

Languagesbashpythondockerfile

Target softwareCisco Secure Firewall Management Center (simulated)

Attack typescommand injection

Evidence & reasoningClassification basis · observed behavior · safety review

Technical evidence

Classification basis and observed behavior

Classification basis

The artifact contains a script (exploit.sh) that actively sends a payload designed to trigger command execution on a target. The README confirms it is a simulation demonstrating the impact of CVE-2025-20265, and the script's behavior is to exploit a command injection vulnerability, not merely detect it.

exploit.sh:1-8README.md:3

Requirements

Target server must be running the simulated FMC service on a reachable network port.exploit.sh:3-4

Observed behavior

Constructs a JSON payload containing a shell command prefixed with 'CMD:' and sends it via HTTP POST to the /api/config endpoint.exploit.sh:5-8
The default command executed is 'cat /opt/flag.txt', demonstrating arbitrary command execution.exploit.sh:5

Safety-review evidence

Behaviors behind the backdoor verdict

Observables

Educational Simulation: README.md describes the artifact as a minimal, educational simulation demonstrating the impact class of CVE-2025-20265 for local learning only.Establishes the intended benign purpose of the code, consistent with the absence of backdoor behavior.README.md:3
Command Execution Mechanism: exploit.sh constructs a JSON payload with a user-supplied command and sends it via curl to a local server endpoint /api/config.This is the normal exploit behavior against the stated target (a local simulation server). It does not exhibit concealed or unrelated harmful actions.exploit.sh:5-8

Review boundaries

What the analysis did not establish

The server-side code (server.py) that processes the injected command is not included in the evidence, so the exact mechanism of command execution cannot be confirmed.
The artifact is a simulation and does not target a real Cisco FMC instance.
Three text files (server.py, entrypoint.sh, and three unclassified files) are omitted from the supplied evidence; their content is not reviewed.
The review is limited to static analysis of the provided text excerpts; no dynamic execution or binary analysis was performed.

Model interpretation

This review is limited to the supplied PoC code and context. It does not assert that the code works or is safe to execute.

Docker lab environments

GitHub

Repository root

Created 2025-09-20Vuln labCVE-2025-20265Dockerfile

1 Dockerfile

Analysisdeepseek-v4-pro:cloud · 2026-08-07

Environment assessment

A single-container Docker environment running a Python HTTP server that simulates a Cisco FMC-style management API. The server intentionally executes shell commands from crafted JSON input for local educational purposes.

Dockerfile:1-15server.py:1-70README.md:1-11

Lab assessment

Vulnerability lab

The README explicitly states it is an educational simulation demonstrating the impact class of a management-plane parsing RCE, inspired by CVE-2025-20265. The server.py contains intentionally unsafe code that executes commands from input, and an exploit.sh script is provided to trigger it.

README.md:1-3server.py:1-10server.py:42-55

Lab shapeDockerfile

ServicesUnknown

Compose manifests0

Dockerfiles1

Evidence & reasoningComponents · CVE assessment · exercise context · review boundaries

Components

Services and files described by the evidence

server.py

vulnerable targetHTTP API server

A Python HTTP server listening on port 8444 that accepts POST requests to /api/config. If the JSON body contains a 'run' field starting with 'CMD:', it executes the remainder as a shell command via subprocess.Popen with shell=True, returning the output.

server.py:1-70server.py:42-55

exploit.sh

exploit scriptproof-of-concept

A bash script that sends a POST request to the server's /api/config endpoint with a JSON payload containing a 'run' field set to 'CMD:<command>'. By default, it attempts to read /opt/flag.txt.

exploit.sh:1-8

entrypoint.sh

container entrypointflag generator

Generates a random flag, writes it to /opt/flag.txt, sets permissions, and then starts the Python server.

entrypoint.sh:1-8

Dockerfile

container build definition

Defines the container image based on python:3.11-slim, copies the server, entrypoint, and exploit scripts, exposes port 8444, sets a healthcheck, and runs entrypoint.sh.

Dockerfile:1-15

CVE assessment

How the supplied evidence relates each vulnerability

CVE-2025-20265

Insufficient evidence

The README states the simulation is 'inspired by CVE-2025-20265', but no details about the actual CVE (affected product, vulnerable code, patch) are provided. The lab's intentionally vulnerable code is a generic command injection, not a reproduction of a specific CVE. The association is claimed but not substantiated by the supplied evidence.

README.md:1-3

Exercise context

Requirements and sequence described by the evidence

Prerequisites

Docker must be installed to build and run the container.README.md:5-9
The container must be built and running, with port 8444 mapped to the host.README.md:7-9

Evidence-described exercise path

Build the Docker image using the provided Dockerfile.README.md:8
Run the container, mapping port 8444.README.md:9
Execute exploit.sh to send a crafted POST request that triggers command execution (default: cat /opt/flag.txt).exploit.sh:1-8

Safety-review evidence

Behaviors behind the stored safety assessment

No harmful behavior observed

All visible behavior is directed at the lab's own target container. The server intentionally executes commands from input, but only within the container. The exploit script targets the container's localhost. No evidence of host escape, external connections, persistence, credential theft, or destructive behavior is present.

server.py:42-55exploit.sh:4-7Dockerfile:1-15

Review boundaries

What the analysis did not establish

The file DISCLAIMER.md is listed in the inventory but its content is not included in the evidence files.
No compose file is present; the environment is a single Dockerfile, so multi-service interactions cannot be assessed.
The association with CVE-2025-20265 is only a claim in the README; no CVE details or patch are provided to verify the link.

Model interpretation

This review is limited to the supplied lab evidence packet. It does not assert that the environment runs, reproduces a vulnerability, or is safe to execute. Contract: eip-docker-lab-analysis-v1.

Linked vulnerabilities

CVE-2025-20265