vulnerability / NVI-00017686 / Revision 1
oras-go: Malicious registry can hijack Bearer token realm to exfiltrate credentials and refresh tokens
GitHub lists this reviewed advisory for oras.land/oras-go/v2, oras.land/oras-go. 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.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
oras.land/oras-go/v2
source listed< 2.6.1
## Summary oras-go's `auth.Client` follows the `realm` URL from a registry's `WWW-Authenticate: Bearer` challenge without validating its scheme or host. The `realm` field is server-controlled by design in the OCI/distribution spec — registries legitimately point token requests at a separate auth endpoint (e.g. Docker Hub's `registry-1.docker.io` -> `auth.docker.io`), so cross-host realms on public DNS names are not in themselves a vulnerability. Two specific patterns, however, are never legitimate under any registry trust model and can be abused by a malicious or compromised registry (or a man-in-the-middle on a plaintext connection): 1. **SSRF to internal networks.** A realm of `http://169.254.169.254/...` (AWS/Azure IMDS), `http://10.0.0.x/...` (RFC 1918), or `http://127.0.0.1/...` causes oras-go running on a cloud VM or corporate workstation to issue outbound HTTP requests from inside the user's trust boundary to an endpoint the user did not choose. The user's stored credentials are attached to those requests, but the principal harm is the network primitive — probing internal endpoints from the client. On IMDSv1 the response body is recoverable from log channels; on IMDSv2 the
oras.land/oras-go
source listed<= 1.2.7
## Summary oras-go's `auth.Client` follows the `realm` URL from a registry's `WWW-Authenticate: Bearer` challenge without validating its scheme or host. The `realm` field is server-controlled by design in the OCI/distribution spec — registries legitimately point token requests at a separate auth endpoint (e.g. Docker Hub's `registry-1.docker.io` -> `auth.docker.io`), so cross-host realms on public DNS names are not in themselves a vulnerability. Two specific patterns, however, are never legitimate under any registry trust model and can be abused by a malicious or compromised registry (or a man-in-the-middle on a plaintext connection): 1. **SSRF to internal networks.** A realm of `http://169.254.169.254/...` (AWS/Azure IMDS), `http://10.0.0.x/...` (RFC 1918), or `http://127.0.0.1/...` causes oras-go running on a cloud VM or corporate workstation to issue outbound HTTP requests from inside the user's trust boundary to an endpoint the user did not choose. The user's stored credentials are attached to those requests, but the principal harm is the network primitive — probing internal endpoints from the client. On IMDSv1 the response body is recoverable from log channels; on IMDSv2 the
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-xf85-363p-868w ↗
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.