Third-pass audit finding. renderShell auto-linkifies any https?:// in
body lines so the manageUrl line becomes a clickable link in the HTML
email. The same regex would happily turn a malicious URL injected into
a user-controlled field (member display_name, equipment / class / form
title, submitter label, space name) into a clickable link.
In Phase 2 dues emails this was self-only: the recipient is the same
member whose display_name appears, so self-phishing is silly. Phase 4
introduces the first email type where one user's display_name lands in
a different user's inbox: form_submission_admin embeds the submitter's
display_name (or, when the form was submitted anonymously and an email
match attributed it to a member, that member's display_name) in an
email read by every forms.manage holder. An authenticated member can
set display_name to "Click https://evil.com for free stuff", submit a
form, and the admin's inbox now has a clickable phishing URL.
body.email is Zod-validated against email format so the typed-email
path is closed, but display_name (z.string().min(1).max(100)) is a
free string. No format restriction will catch a determined attacker.
Mitigation: stripUrls(s) replaces https?://\S+ with [link]. Applied to
every user-controlled input across all four renderers (dues, booking,
class, form) including spaceName, memberName / recipientName, equipment
/ class / form title, location, and submitterLabel. manageUrl, which
buildManageUrl constructs from NEXT_PUBLIC_APP_URL or a Stripe-
authenticated webhook host, stays untouched and remains the only
linkified URL in the rendered email.
5 new tests cover the new attack vector (form_submission_admin) and
defense-in-depth across booking, class, and dues renderers. Suite 572,
build clean.
Moheeb Zara
09f293e3c1