Insecure deserialization

SkillAI & models

Insecure deserialization → RCE via gadget chains. Load when the app deserializes attacker data: Java (rO0/AC ED base64), PHP `unserialize` (O:), Python pickle, .NET BinaryFormatter/ViewState, Ruby Marshal/YAML. Signals: serialized blobs in cookies/params, `__VIEWSTATE`, `rO0AB`, `O:8:`.

Instructions available. Your AI can read the instructions. Execution depends on the setup they require.

Account requirements not reviewed. Check the skill instructions before use; ahel provides instructions and does not run this skill.

Add ahel to your AI once: Claude, ChatGPT, Cursor, Claude Code or Codex. Then ask it to use this.

Then ask your AI: use the Insecure deserialization skill

What this skill tells your AI

The instructions your AI receives, as published by noorqureshi/sploitagent in skills/web/web-deserialization/SKILL.md and read by ahel’s review.

When it applies

The app takes serialized objects from the client (cookies, hidden fields, params, message queues) and deserializes them. Recognizable by format markers.

Why it works

Deserialization reconstructs objects and can invoke their methods (magic methods, readObject, __wakeup). A crafted object graph ("gadget chain") strings together existing library methods to reach a dangerous sink — command execution — during/after deserialization.

Method

Payloads & full variation set: cheatsheet.md next to this file — work the set, not the first line.

Spot the blob & format: Java rO0AB/AC ED 00 05, PHP O:8:"...":, .NET __VIEWSTATE/AAEAAAD, Python pickle, Ruby Marshal \x04\x08.
Confirm it's deserialized untrusted: tamper a byte → parse error/behaviour change.
Generate a gadget chain with the right tool for a library on the classpath:
- Java: ysoserial CommonsCollections1 'curl <collab>' | base64
- PHP: phpggc Monolog/RCE1 system id (pick a gadget matching a loaded framework)
- .NET: ysoserial.net (ViewState needs the MAC key or MAC-disabled).
Deliver in the sink; start with an OOB command (curl/nslookup to your host) as safe proof.

Gotchas

The chain must match a library actually present (Commons-Collections version, Monolog, etc.) — enumerate dependencies.
Java: prefer a DNS/OOB gadget to confirm before an RCE payload.
.NET ViewState needs the machineKey unless MAC validation is off — check for leaked web.config.

Verify success

An OOB callback or command output proving code executed during deserialization.

References

ysoserial / phpggc / ysoserial.net; PortSwigger deserialization labs; OWASP.

Signals

GitHub stars: 20
Forks: 7
Last commit: Sep 2026

Advanced

Item type: skill
Key: web-deserialization-noorqureshi
Source: github.com/noorqureshi/sploitagent

github.com/noorqureshi/sploitagent