Java Serialization Audit

Q: What does the Java Serialization Audit AI skill do?

Java 源码序列化类漏洞审计。当在 Java 白盒审计中需要检测序列化/反序列化相关漏洞时触发。 覆盖 3 类风险: Java 原生反序列化(ObjectInputStream/Gadget Chain/ysoserial)、 XXE(DocumentBuilderFactory/SAXParser/XMLInputFactory/TransformerFactory/SchemaFactory 五种解析器)、 模板注入 SSTI(Velocity/FreeMarker/Thymeleaf 模板引擎代码执行)。 Java 反序列化是 Java 生态最具特色的高危漏洞类型，Gadget Chain 分析是核心难点。

OrganizationPopular

wgpsec

java-serialization-audit

Java 源码序列化类漏洞审计。当在 Java 白盒审计中需要检测序列化/反序列化相关漏洞时触发。覆盖 3 类风险: Java 原生反序列化(ObjectInputStream/Gadget Chain/ysoserial)、 XXE(DocumentBuilderFactory/SAXParser/XMLInputFactory/TransformerFactory/SchemaFactory 五种解析器)、模板注入 SSTI(Velocity/FreeMarker/Thymeleaf 模板引擎代码执行)。 Java 反序列化是 Java 生态最具特色的高危漏洞类型，Gadget Chain 分析是核心难点。

Overview

Publisher	wgpsec
Repository	`AboutSecurity`
Skill name	`java-serialization-audit`
Stars	1.7K
Forks	242
Bundled files	1
Links	Skill source Repository

Markdown instructions
A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.
Works with any LLM
AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.
1 bundled files
Scripts, templates, and references the model can read while it works. Files are read-only and never executed.
Open source
Published by wgpsec on GitHub. Read the source before you install it.

Installation

Install the Java Serialization Audit AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

Open the app and go to Plugins → Skills.
Choose "Install from GitHub".
Paste the skill folder URL below and confirm.
Enable the skill in any chat where you want it available.

Store

Installed

Skills

Add skills

Import one or more skills from a public GitHub folder or a local .skill or .zip archive, or SKILL.md file.

From GitHub URLFrom .skill, .zip, or SKILL.md

GitHub repo or folder

https://github.com/wgpsec/AboutSecurity/tree/master/skills/code-audit/java/java-serialization-audit

Points to a single skill folder, or any folder that contains multiple skills. Public repos only.

CancelContinue

Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills

git clone --depth 1 https://github.com/wgpsec/AboutSecurity.git /tmp/AboutSecurity
mkdir -p .claude/skills
cp -r /tmp/AboutSecurity/skills/code-audit/java/java-serialization-audit .claude/skills/java-serialization-audit

Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Java Serialization Audit in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Java Serialization Audit on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Java Serialization Audit is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

Loaded only when it is needed
The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.
Switch models mid-chat
Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Java 序列化类漏洞源码审计

本 skill 聚焦源码层面判断"反序列化/XXE/SSTI 是否成立"，核心工作是：白盒确认反序列化入口点、追踪数据来源、评估 classpath 中可用 Gadget 链、验证 XML 解析器安全配置、检查模板引擎渲染上下文。构造 exploit payload、远程利用链发送等运行时黑盒技术属于对应 exploit skill 范畴。

深入参考

3 类漏洞的危险模式 / 安全模式代码对比 / Gadget 依赖表 / EVID 证据示例 → references/serialization-patterns.md

3 类漏洞速查表

类型	典型 Sink	利用条件	严重度
Java 反序列化	`ObjectInputStream.readObject()`, `XMLDecoder.readObject()`	用户可控序列化流 + classpath 存在可用 Gadget Chain	Critical
XXE	`DocumentBuilderFactory`, `SAXParser`, `XMLInputFactory`, `TransformerFactory`, `SchemaFactory`	外部实体/DTD 未禁用 + 用户可控 XML 输入	High-Critical
SSTI	`Velocity.evaluate`, `FreeMarker Template`, Thymeleaf 预处理表达式	用户输入直接进入模板编译/渲染上下文	Critical

Java 反序列化审计要点

入口点识别: ObjectInputStream.readObject()、ObjectInputStream.readUnshared()、XMLDecoder.readObject()、自定义 readObject/readResolve/readExternal 实现中的额外攻击面
数据来源追踪: HTTP 请求 body（魔术字节 AC ED 00 05 或 Base64 编码 rO0AB）、RMI/JMX 远程调用、JMS 消息队列、Redis/Memcached 缓存反序列化、文件读取、ViewState、Cookie/Session 序列化存储
Gadget 可用性评估: 检查 pom.xml/build.gradle 及 classpath 中是否存在已知 Gadget 链的依赖库（commons-collections 3.x/4.x、commons-beanutils、spring-core、Groovy、hibernate-core 等），版本是否在受影响范围内
防御机制验证: JEP 290 ObjectInputFilter 是否配置、白名单 vs 黑名单策略、SerialKiller/NotSoSerial 等第三方防护库是否启用、resolveClass 是否被重写为白名单校验
readResolve/readObject 自定义逻辑: 即使不存在通用 Gadget，自定义反序列化方法中的文件操作、网络请求、动态类加载等行为也构成攻击面

XXE 审计要点

5 种 XML 解析器安全配置:
- DocumentBuilderFactory: setFeature("http://apache.org/xml/features/disallow-doctype-decl", true)
- SAXParserFactory: 同上 + setFeature("http://xml.org/sax/features/external-general-entities", false) + setFeature("http://xml.org/sax/features/external-parameter-entities", false)
- XMLInputFactory (StAX): setProperty(XMLInputFactory.SUPPORT_DTD, false) + setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false)
- TransformerFactory: setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "") + setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "")
- SchemaFactory: setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "") + setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, "")
数据流分析: XML 输入来源（HTTP 请求体、文件上传、SOAP 消息、SVG/Office 文件） → 进入解析器 → 解析结果回显（直接 XXE）或无回显（盲注/带外 OOB）
Java 特有协议: jar: 协议可触发远程文件下载与解压、netdoc: 协议（旧版 JDK）等价于 file://

模板注入 SSTI 审计要点

Velocity: Velocity.evaluate(context, writer, tag, userTemplate) — 若 userTemplate 参数用户可控则直接 RCE
FreeMarker: new Template("t", new StringReader(userInput), cfg).process(dataModel, writer) — 用户输入作为模板源编译即危险
Thymeleaf: 控制器返回值拼接导致 SSTI，return "user/" + input 时 input 可注入 __${expr}__ 预处理表达式触发 SpEL → RCE
安全模式: 模板名/路径白名单、FreeMarker 设置 TemplateClassResolver.ALLOWS_NOTHING_RESOLVER 禁用 ?new() 内建函数、Velocity 使用 SecureUberspector、Thymeleaf 限制视图名不可拼接用户输入

检测清单

Bundled files

The model reads these on demand while the skill is loaded. They are exposed as readable files and are never executed.

references/serialization-patterns.md13 KB

Frequently asked questions

What does the Java Serialization Audit AI skill do?

Why use Java Serialization Audit on TypingMind?

Because you install it once and use it with any model. Java Serialization Audit is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Java Serialization Audit in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/wgpsec/AboutSecurity/tree/master/skills/code-audit/java/java-serialization-audit. TypingMind reads its SKILL.md and bundles its files and installs it as a skill you can enable per chat.

Which AI models can use Java Serialization Audit?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Java Serialization Audit?

As many as you like. As long as a model supports skills, you can use Java Serialization Audit with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Java Serialization Audit AI skill free?

It is published on GitHub by wgpsec. Check the repository for licensing terms. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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Finishing A Development Branch

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CommunityPopular

Use when implementation is complete, all tests pass, and you need to decide how to integrate the work

Receiving Code Review

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CommunityPopular

Use when receiving code review feedback, before implementing suggestions, especially if feedback seems unclear or technically questionable - requires technical rigor and verification, not performative…

Requesting Code Review

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CommunityPopular

Use when completing tasks, implementing major features, or before merging to verify work meets requirements

Systematic Debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes

Overview

Installation

Install in TypingMind

Install in another agent

Use it in TypingMind

Works with any AI model

Skill instructions

Java 序列化类漏洞源码审计

深入参考

3 类漏洞速查表

Java 反序列化审计要点

XXE 审计要点

模板注入 SSTI 审计要点

检测清单

Bundled files

Frequently asked questions

Related AI Skills

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