The Document Object Model (DOM) is a web browser's hierarchical representation of the elements on the page. Websites can use JavaScript to manipulate the nodes and objects of the DOM, as well as their properties. DOM manipulation in itself is not a problem. In fact, it is an integral part of how modern websites work. However, JavaScript that handles data insecurely can enable various attacks. DOM-based vulnerabilities arise when a website contains JavaScript that takes an attacker-controllable value, known as a source, and passes it into a dangerous function, known as a sink.
| DOM-based vulnerability | Example sink |
|---|---|
| DOM XSS LABS | document.write() |
| Open redirection LABS | window.location |
| Cookie manipulation LABS | document.cookie |
| JavaScript injection | eval() |
| Document-domain manipulation | document.domain |
| WebSocket-URL poisoning | WebSocket() |
| Link manipulation | element.src |
| Web message manipulation | postMessage() |
| Ajax request-header manipulation | setRequestHeader() |
| Local file-path manipulation | FileReader.readAsText() |
| Client-side SQL injection | ExecuteSql() |
| HTML5-storage manipulation | sessionStorage.setItem() |
| Client-side XPath injection | document.evaluate() |
| Client-side JSON injection | JSON.parse() |
| DOM-data manipulation | element.setAttribute() |
| Denial of service | RegExp() |
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