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Defending Applications

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telagod
defending-applications

Application security defense knowledge for builders. Covers Web/API/GraphQL hardening (XSS/SQLi/SSRF/IDOR/BOLA/Mass Assignment/deserialization/upload/path traversal), authentication/authorization (OAuth 2.0/OIDC/JWT/Session/Cookie/SAML/SSO), and LLM application security (prompt injection, jailbreak, RAG poisoning, agent privilege escalation, output filtering). Use when designing or reviewing application-layer defenses, fixing CVE-class bugs in your own code, hardening auth flows, or threat-modeling LLM-powered features. For offensive testing see securing-systems/pentest, for incident response see securing-systems/blue-team, for infra-layer hardening see provisioning-infrastructure.

Overview

Publishertelagod
Repositorycode-abyss
Skill namedefending-applications
Stars
242
Forks
33
Bundled files
3
LicenseMIT
Links
  • 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.

  • 3 bundled files

    Scripts, templates, and references the model can read while it works. Files are read-only and never executed.

  • Open source

    Published by telagod on GitHub. Read the source before you install it.

Installation

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

1

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.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
    https://github.com/telagod/code-abyss/tree/main/skills/defending-applications
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

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/telagod/code-abyss.git /tmp/code-abyss
mkdir -p .claude/skills
cp -r /tmp/code-abyss/skills/defending-applications .claude/skills/defending-applications
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Defending Applications 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 Defending Applications 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 Defending Applications 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.

应用安全防御 · 镇魔甲

判断先于执行:决定「是否做 / 选什么 / 如何取舍」(栈、方案、架构、权衡)前,先读领域判断内核 skills/_kernel/security/SKILL.md——它管 judgment,本秘典管 execution;冲突时以内核判断为准。

开发侧防御秘典:站在 builder 一侧,把漏洞挡在合并前。 不教渗透,只教"如何写出杀不动的代码"和"如何把已生漏洞最小代价闭环"。 信级:项目源码/lock 文件 > 框架官方安全文档 > CVE/CWE > 训练记忆(标 [unverified])。

路由

意图加载触发词
Web/API/GraphQL 漏洞防御web-api-appsecXSS, SQLi, SSRF, BOLA, IDOR, Mass Assignment, GraphQL, 反序列化, 文件上传, 路径遍历, XXE, OWASP
认证授权与会话oauth-and-sessionsOAuth, OIDC, JWT, SSO, SAML, Session, Cookie, PKCE, refresh token, kid 注入
LLM 应用安全llm-appsecPrompt 注入, 越狱, 越权调用, RAG 投毒, agent tool 滥用, 输出过滤, jailbreak

何时使用

场景使用本 skill使用其他
review 自家代码、修 CVE、设计鉴权✅ 本 skill—
写 SAST 规则、Semgrep 模式✅ 本 skill + securing-systems/code-audit—
设计 LLM 应用的 guardrail✅ llm-appsec+ building-agent-systems/llm-security
红队渗透、写 PoC 攻击目标❌securing-systems/pentest
处理已发生的入侵、日志取证❌securing-systems/blue-team
容器/K8s/CI 加固❌provisioning-infrastructure
设计零信任、身份架构部分(OAuth/SSO 内)architecting-security

联动

  • securing-systems/code-audit:本 skill 给"怎么修",code-audit 给"怎么找"。
  • securing-systems/pentest:攻方视角验证本 skill 的修复是否真正闭环。
  • analyzing-security:自动化扫描胶水;本 skill 提供规则语义。
  • building-agent-systems/llm-security:agent 内部细节;本 skill 关注应用边界。
  • designing-architectures:威胁建模、API 设计;本 skill 关注落地代码。

执行链

威胁建模 → 入口梳理 → source→sink 追踪 → 防御层选型 → 最小修复 → 回归测试 → 检测信号埋点

每个漏洞的修复必须回答三问:

  1. 入口在哪:用户可控数据从哪进来(route/header/cookie/body/file/upstream API/RAG doc)。
  2. 信任边界在哪:何处由"untrusted"变"trusted",是否有显式校验。
  3. 检测信号是什么:修复后若被绕过,哪条日志/指标会响。

铁律

  1. 服务端为真:前端校验只是 UX,所有 authz/sanitize 必须在服务端再做一次。客户端代码即攻击面。
  2. deny by default:authz、CORS、CSP、SQL where 子句、文件类型——所有名单皆 allowlist 优先,blacklist 是反模式。
  3. 不信任 ID:URL/body 里的 object_id 永远先做 ownership 校验,再做业务逻辑。BOLA 是 API 漏洞之王。
  4. 可观测优先于完美防御:每个高风险路径必须有结构化日志 + 速率/异常告警,被绕过时能 5 分钟内发现。
  5. 修复要带回归:每个漏洞修复必须配 1 个攻击用例测试 + 1 个正常用例测试,否则六个月后必复发。

输出约束

  • 漏洞示例代码统一 ❌ 错代码 / ✅ 正代码 对比,错代码必须能跑通漏洞场景。
  • 攻击演示用 example.com / RFC 5737 网段(192.0.2.0/24);token/密钥用 <REDACTED>。
  • 给修复方案时同时给:检测信号(log key / metric name)、回归测试骨架、性能/兼容回归点。

Bundled files

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

Frequently asked questions

What does the Defending Applications AI skill do?

Application security defense knowledge for builders. Covers Web/API/GraphQL hardening (XSS/SQLi/SSRF/IDOR/BOLA/Mass Assignment/deserialization/upload/path traversal), authentication/authorization (OAuth 2.0/OIDC/JWT/Session/Cookie/SAML/SSO), and LLM application security (prompt injection, jailbreak, RAG poisoning, agent privilege escalation, output filtering). Use when designing or reviewing application-layer defenses, fixing CVE-class bugs in your own code, hardening auth flows, or threat-modeling LLM-powered features. For offensive testing see securing-systems/pentest, for incident respon...

Why use Defending Applications on TypingMind?

Because you install it once and use it with any model. Defending Applications 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 Defending Applications in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/telagod/code-abyss/tree/main/skills/defending-applications. 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 Defending Applications?

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 Defending Applications?

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

Is the Defending Applications AI skill free?

Yes. It is published on GitHub by telagod under the MIT license. 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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