vulnerability / NVI-00012946 / Revision 1
9router: Image prefetch DNS rebinding allows SSRF to internal services
GitHub lists this reviewed advisory for 9router. 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.
7.4 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.
9router
source listed<= 0.4.80
## Summary 9router validates image URLs by resolving the host before fetching, but the later server-side fetch performs a separate DNS resolution. An attacker-controlled DNS name can resolve to a public IP during validation and then rebind to an internal Docker/private IP during the fetch. This allows the server-side image prefetch to reach internal-only HTTP services (SSRF). ## Details - **Affected version / commit:** 9router `v0.4.80` @ `b282f05`. - **Reachable through** `/v1/chat/completions` with a **vision-capable model** and an `image_url` content part. A vision-capable model name is required so the image survives modality stripping and the server-side prefetch is armed. - The provider used in this reproduction is the bundled **mock provider** — **no real API key and no real provider call**. - **internal-admin** (the SSRF target) is **not exposed to the host network**; it is reachable only from inside the Docker network. - **rebind-dns** behaviour for `rebind.9r.test`: - first A response → `1.1.1.1` (public) to pass the public-host guard, - second A response → `172.29.0.10` (internal-admin) during the fetch. - **internal-admin** logs `GET /ssrf-marker` with `pe
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-cmhj-wh2f-9cgx ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.