# stephenbradshaw/vulnserver

Vulnerable server used for learning software exploitation

Repository: https://github.com/stephenbradshaw/vulnserver
Canonical: https://ross.abutalabs.com/products/vulnserver
Language: C
License: BSD-3-Clause
License Family: permissive
Last push: 2020-10-09T00:40:05+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4483, "days_push": 2155, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1133, forks 267 (observed 2026-08-28T04:03:42.883306+00:00)

## What it is
Vulnserver is a deliberately vulnerable multithreaded Windows TCP server containing multiple subtly different buffer overflow bugs. It is designed purely as a safe target for learning how to discover and exploit software vulnerabilities.

## Use cases
- practice finding buffer overflow vulnerabilities
- learn exploit development with a safe target
- test fuzzing tools like SPIKE against a known-vulnerable server
- practice SEH-based and egghunter exploits
- teach reverse engineering and debugging skills
- set up a lab for penetration testing training

## When to choose
- you are learning or teaching software exploitation
- you need a legal, intentional target for fuzzing practice
- you want varied buffer overflow challenges in one program

## When to avoid
- you need a functional server for production use
- you cannot run Windows binaries
- you want a real-world vulnerable application

## Facets
- artifact type: application
- maturity: maintenance
- function: security, penetration-testing, http-server
- domain: security, penetration-testing, education, developer-tools
- platform: windows, cross-platform
- tags: exploit-development, buffer-overflow, vulnerable-app, fuzzing-target, learning-tool, tcp-server

## Member repositories
- stephenbradshaw/vulnserver (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:42.883306+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:37:28.388809+00:00, confidence not recorded.
  - readme: https://github.com/stephenbradshaw/vulnserver (fetched 2026-08-28T04:03:42.883306+00:00, sha def32ed1cfd4)
- Data as of 2026-08-30T08:39:29.467469+00:00.