Executive brief
Froxlor is a web hosting control panel that manages customer email accounts and sender aliases (approved sender identities). A flaw in the sender alias deletion feature fails to verify that an authenticated customer owns the alias being accessed, allowing customers to view other customers' allowed sender addresses by manipulating request parameters. This enables cross-customer data exposure without requiring additional privileges or user interaction.
Technical details
The vulnerability is an improper access control flaw (CWE-200) in customer_email.php's sender alias deletion confirmation flow. The code retrieves sender alias data using only a global auto-increment ID parameter (senderid) without scoping the query to the current customer or their mailbox. An authenticated customer can enumerate sender alias IDs and craft requests to view foreign aliases by supplying arbitrary senderid values in delete confirmation requests. The allowed_sender value is then disclosed in the HTML confirmation dialog. The actual delete operation does validate ownership, preventing unauthorized deletion, but the confirmation page renders the queried data before that check. Fix: version 2.3.7 and later scope sender alias lookups to the current customer and mailbox before rendering the confirmation.
Affected products
- Froxlor Froxlor before 2.3.7
Timeline
- 2026-05-29: disclosed: GitHub Security Advisory (GHSA-mr9h-45p9-fg8h) published
- 2026-09-14: advisory: CVE-2026-90936 published on NVD
- 2026: patched: Fixed in Froxlor 2.3.7