The SSRF section is the most important part for any tool that fetches a user supplied URL. Resolving the hostname yourself and checking the IP against private ranges after every redirect matters, since a public URL can redirect to 169.254.169.254 or a DNS record can change between check and fetch. A strict timeout and a response size cap also keep one slow target from tying up the rate limited workers.
StackShortlist
Proof Over Promises.
The SSRF section is the most important part for any tool that fetches a user supplied URL. Resolving the hostname yourself and checking the IP against private ranges after every redirect matters, since a public URL can redirect to 169.254.169.254 or a DNS record can change between check and fetch. A strict timeout and a response size cap also keep one slow target from tying up the rate limited workers.