vulnerability / NVI-00015179 / Revision 1
Astro: Host header SSRF in prerendered error page fetch
GitHub lists this reviewed advisory for astro. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
astro
source listed< 6.4.6
## Summary Astro SSR apps with prerendered error pages (`/404` or `/500` using `export const prerender = true`) fetch those pages over HTTP at runtime when an error occurs. The URL for this fetch is derived from `request.url`, which in turn gets its origin from the incoming `Host` header. When the `Host` header is not validated against `allowedDomains`, an attacker can point the fetch at an arbitrary host and read the response. ## Who is affected This affects SSR deployments that: 1. Have a prerendered 404 or 500 page 2. Use `createRequestFromNodeRequest` from `astro/app/node` with `app.render()` **without** overriding `prerenderedErrorPageFetch` — this includes custom servers built on the public API and third-party adapters **Not affected:** - `@astrojs/node` >= 9.5.4 (reads error pages from disk) - `@astrojs/cloudflare` (uses the ASSETS binding) - The dev server (renders error pages in-process) ## How it works `createRequestFromNodeRequest` builds `request.url` from the raw `Host` / `:authority` header. The `allowedDomains` option is accepted but only gates `X-Forwarded-For` — it does not constrain the URL origin. (The public `createRequest` does fall back to `localhost` f
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-2pvr-wf23-7pc7 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.