Cross-site scripting (reflected DOM-based)
Summary: Reflected DOM-based vulnerabilities occur when data from a request is echoed into the application's immediate response inside a part of the DOM that a client-side script then processes unsafely. PortSwigger notes that an attacker can use this reflection to control part of the response, such as a JavaScript string, and construct a URL that executes attacker-supplied JavaScript in another user's browser within their session.
Bottom line: The attacker-supplied code can steal the victim's session token or login credentials, perform arbitrary actions on their behalf, and log their keystrokes - and PortSwigger warns that static analysis alone can flag false positives, so a finding without dynamic evidence still needs code review to confirm whether it is exploitable.
Read the original at PortSwigger Research ↗
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