What happened
Logto <1.43.0 fetches administrator-controlled outbound destinations (webhook delivery, custom OAuth2 userInfoEndpoint forwarding the OAuth access token in the Authorization header, OIDC jwksUri) without validating the connection address, so webhooks/connectors can reach special-use and cloud-metadata addresses and expose internal data or upstream provider credentials. Fixed in 1.43.0.
Why it matters
In AI app auth infrastructure, cloud-metadata (IMDS) reachable from authenticated admin-driven outbound fetches can be used to pivot to instance credentials that AI workloads hold, and OAuth2 connectors forward user access tokens to attacker-selected endpoints - SSRF plus OAuth token exfiltration in the auth layer of AI apps.
Attack vector
Administrator-configured webhook/connector URL targets special-use or cloud-metadata addresses, or attacker-selected userInfoEndpoint/jwksUri forwards OAuth tokens during connector fetch.
Affected systems
Logto < 1.43.0 (AI/auth infrastructure)
Mitigation
Upgrade to Logto 1.43.0+; validate/SSRF-guard outbound hook destinations.