Lychee SSRF Protection Bypass

Incomplete IP validation in Lychee's SSRF protection mechanism allows authenticated users to bypass all four security configuration settings by leveraging loopback and link-local addresses, enabling access to internal services. The vulnerability affects Lychee versions prior to 7.5.1 and requires prior authentication but carries low confidentiality impact. No public exploit code or active exploitation has been identified at time of analysis, though the attack vector is network-accessible and requires minimal complexity.

DNS rebinding bypasses SSRF protection in Lychee photo-management tool versions prior to 7.5.2, allowing authenticated remote attackers to access restricted internal resources by providing domain names instead of IP addresses to the photo URL import feature. The vulnerability exploits a logic flaw in PhotoUrlRule.php where hostname validation only applies to IP addresses, leaving domain-based requests unvalidated. Vendor-released patch available (version 7.5.2); no public exploit identified at time of analysis.