CyberGuard dictionary / Web Application Security
Server-Side Request Forgery
Also known as SSRF
A flaw that lets an attacker induce a server to send a request to an unintended destination.
In simple terms
A website fetches an address supplied by a visitor without checking where it leads.
Technical explanation
SSRF can reach internal services, cloud metadata, or private networks unless destinations and redirects are controlled.
The vulnerable server makes a request chosen or influenced by an untrusted user, potentially crossing a network boundary the user cannot reach directly. URL validation must account for redirects and address changes.
Examples in practice
An image-import feature is tricked into requesting an internal management endpoint.
An image fetcher accepts a public URL that redirects to an internal address. The service blocks that destination after each redirect and logs the rejected request.
Why it matters
Server-side fetch features need strict destination and network controls.
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Sources and further reading
Published 2026-10-15 · Last updated 2026-10-15 · CyberGuard editorial content. Source links provide context; they do not imply endorsement.