SSRF Vulnerability Analysis: Remote Instance Sync URL Validation and safe_get Fix Details

Vulnerability Overview This vulnerability involves an issue with the enforcement of outbound URL policies in remote-instance synchronization. Specifically, while the syntax of URLs was validated when the remote instance address was stored, no network boundary checks were performed. This allowed attackers to achieve Server-Side Request Forgery (SSRF) by pointing to internal or cloud metadata HTTP(S) services. Scope of Impact At Storage Time: and the reject non-HTTP(S) URLs and literal IP hostnames (such as private, loopback, link-local, multicast, reserved, or unspecified ranges). At Request Time: parses the host, rejecting any non-publicly resolvable addresses, and manually follows redirects. Therefore, 3xx redirects pointing to internal hosts are rejected rather than followed. Remediation 1. At Storage Time: - Validate the URL syntax of the remote instance address. - Reject non-HTTP(S) URLs and literal IP hostnames. 2. At Request Time: - Use to resolve the host, rejecting any non-publicly resolvable addresses. - Manually follow redirects, rejecting any 3xx redirects that point to internal hosts. 3. Sync Worker: - Retrieve URLs via and treat blocked targets as non-retryable failures. - Add tests for the policy, host resolution, and rejection of redirects to internal addresses. POC Code Summary By enforcing a strict outbound URL policy, this remediation ensures that remote instance addresses comply with security standards both at storage and request time, thereby preventing Server-Side Request Forgery (SSRF) attacks.

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SSRF Vulnerability Analysis: Remote Instance Sync URL Validation and safe_get Fix Details

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