GHSA-x35m-3gp4-4fh5
etcd RBAC bypass allows unauthorized data access via PrevKv/lease attachment in nested transaction Put requests
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | go.etcd.io/etcd/v3 | >= 3.6.0, < 3.6.11 | 3.6.11 |
| Go | go.etcd.io/etcd/v3 | >= 3.5.0, < 3.5.30 | 3.5.30 |
| Go | go.etcd.io/etcd | < 3.4.44 | 3.4.44 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
_What kind of vulnerability is it? Who is impacted?_
A vulnerability in etcd allows read access via PrevKv, or lease attachment in Put requests within transaction operations, to bypass RBAC authorization checks. An authenticated user without sufficient read or lease-related permissions may be able to access unauthorized data or attach leases by invoking transaction operations with these features enabled.
Kubernetes does not rely on etcd’s built-in authentication and authorization. Instead, the API server handles authentication and authorization itself, so typical Kubernetes deployments are not affected.
### Patches
_Has the problem been patched? What versions should users upgrade to?_
This vulnerability is patched in the following versions:
- etcd 3.6.11
- etcd 3.5.30
- etcd 3.4.44
### Workarounds
_Is there a way for users to fix or remediate the vulnerability without upgrading?_
If upgrading is not immediately possible, reduce exposure by treating the affected
RPCs as unauthenticated in practice.
- restrict network access to etcd server ports so only trusted components can connect
- require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate
distribution
### Reporters
Samy Ghannad (@SamyGhannad on Github) reported that read access via PrevKv in a Put request within etcd transactions bypassed RBAC authorization checks. Benjamin Wang (@ahrtr ) further analyzed that lease attachment in a Put request within etcd transactions also bypassed RBAC authorization checks
References
External links from the advisory. They lead to third-party sites.