Interactsh

Interactsh is an open-source tool from ProjectDiscovery for detecting out-of-band (OOB) interactions - the callbacks that prove blind vulnerabilities like SSRF, blind XSS, blind SQLi, and log4shell are exploitable. It provides unique callback URLs for DNS, HTTP, SMTP, FTP, and LDAP protocols, and records any interactions that hit those URLs. When testing for blind vulnerabilities, you inject an Interactsh URL as a payload and wait for the target to make a callback, proving the vulnerability exists even when there's no direct response. Interactsh can be self-hosted for privacy or used via the public server at interact.sh. It integrates directly with Nuclei, httpx, and other ProjectDiscovery tools, and provides a web dashboard, CLI client, and API for monitoring interactions in real-time.