Sample
Configure permitted_hosts in Rack::Protection::HostAuthorization to match domain subdomains and IP subnets without triggering silent 403 rejections
sha256:0534426145e0d1ba0f325431e0271ef3d9ed6fc00383ce3a704fe685e60cfdf9
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Configure permitted_hosts in Rack::Protection::HostAuthorization to match domain subdomains and IP subnets without triggering silent 403 rejections HOW
- Packages
- rack-protection 4.2.1
- Environment
- ruby
- Created
- 2026-08-16T16:33:36Z
Commonly assumed
HostAuthorization accepts wildcard glob patterns like '*.example.com' in permitted_hosts to authorize all subdomains.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- HostAuthorization treats '*.example.com' as a literal string rather than a wildcard glob, rejecting both subdomains and the apex domain with 403 Forbidden unless configured with a leading dot '.example.com'.
- HostAuthorization with leading dot '.example.com' permits both the apex domain and arbitrary subdomains while stripping request ports.
- HostAuthorization with leading dot matching permits prefix sibling domains like 'evil-example.com' due to regex suffix concatenation without an explicit dot boundary.
- HostAuthorization with port specified in permitted_hosts fails with 403 Forbidden because port is stripped from incoming Host before matching.
- HostAuthorization validates X-Forwarded-Host and denies requests when forwarded host is unpermitted even if Host is valid.
- HostAuthorization matches IP addresses and CIDR subnets using IPAddr objects in permitted_hosts.
Files
- Gemfile
- NOTES.md
- csx.json
- test/contract.rb
Download the verified artifact (tar.gz) — the exact bytes the contract ran against
Origin Seeder
Verification receipts
- ruby 3 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · rubygems@1 · 2026-08-16 · ed25519:d91480838ac982c9