High advisory for emailflare

Advisory overview

emailflare before commit cf31f33 contains a missing authorization vulnerability in POST /api/inbox/compose that allows authenticated members to send mail as any sender address. Attackers can supply an arbitrary from field, which is passed unchecked to the Cloudflare send call, to impersonate other users or the organization to external recipients.

Related references

• https://github.com/0xdps/emailflare
• https://github.com/0xdps/emailflare/blob/d448ea205937a5e82683f89013d4c23159da5b7d/services/inbox-worker/src/routes/inbox/compose.ts
• https://github.com/0xdps/emailflare/commit/cf31f33bbb4a324d5353b8a5db0312fedc19618f
• https://www.vulncheck.com/advisories/emailflare-before-commit-cf31f33-missing-authorization-via-inbox-compose-endpoint