advanced_config is admin-only, but other fields are written into nginx
config as-is and the schema barely limited them. A non-admin could add
any directive through them:
- location path, forward_host and forward_path (any non-empty string)
- proxy host forward_host (a quote breaks out of set $server "...")
- redirection forward_domain_name and stream forwarding_host (their
pattern allowed ";", e.g. "example.com; return 200; #")
- access list IPv6 addresses ("%.+" zone id allowed "::1%x; allow all")
- domain names (a newline got out of the header comment)
Validation
- New lib/nginx-values.js holds the rules. Values can't contain
characters that end or change an nginx token: whitespace, control
characters, ; { } " ' # \, and no $ in a host. Location paths allow a
modifier and an unquoted or double-quoted URI, so =, ~, ~* and ^~
locations and quoted regexes keep working.
- The API schemas use the same patterns, including the certificate
schema's own copy of the domain rule. A test fails if they drift.
- generateConfig checks stored values again, so rows saved before these
rules can't inject either. The check is about nginx structure only:
a stored value the API would now reject, but which can't add
directives, still renders. If a value is unsafe, nothing is written
and the host is marked offline with the reason in nginx_err. The same
check covers per-location access lists and the Let's Encrypt request
config.
- htpasswd user names can't contain ":" or control characters, which
corrupted the file.
Fixes along the way
- IPv6 client addresses: drop zone ids, which nginx's allow/deny
rejects anyway, and fix broken escapes (literal "d" for digits, an
unescaped ".").
- Rewrite the domain rule used by redirection and stream hosts so it
can't backtrack exponentially. It accepts the same values.
- Pattern errors still say "must match pattern", but no longer quote
the regex.
Tests
- backend/test/nginx-values.test.js, run by `yarn test` and in
scripts/ci/test-and-build. Real request schemas reject an injection
set and accept valid values on every endpoint. Accepted values,
rendered through the real templates and parsed using nginx's
tokenizer rules, keep the same statement structure. The check
refuses unsafe stored rows.
- NginxValues.cy.js: injection attempts from a non-admin get 400, and
hosts using valid edge-case values come up with nginx_online true.
Keep the incoming Host authority for default and custom locations, with the existing hostname fallback when Host is absent. Add a built-image regression that validates Host against Origin and Referer and run it after the CI image build.
Jamie Curnow
lennondotw