Vulnerabilities

etcd is a distributed key-value store for the data of a distributed system. Prior to 3.5.32 and 3.6.13, when etcd is configured with --listen-client-http-urls to split HTTP and gRPC client endpoints onto separate listeners, the --client-crl-file Certificate Revocation List is not enforced on the gRPC listener, allowing a client with a revoked certificate to authenticate successfully over gRPC. This issue is fixed in versions 3.5.32 and 3.6.13.

etcd is a distributed key-value store for the data of a distributed system. Prior to 3.4.44, 3.5.30, and 3.6.11, 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. This vulnerability is fixed in 3.4.44, 3.5.30, and 3.6.11.

etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42, 3.5.28, and 3.6.9, unauthorized users may bypass authentication or authorization checks and call certain etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch, audit, and recovery workflows. 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. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. 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 and/or require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.

Etcd v3.5.4 allows remote attackers to cause a denial of service via function PageWriter.write in pagewriter.go. NOTE: the vendor's position is that this is not a vulnerability.

etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.26 and 3.5.9, the LeaseTimeToLive API allows access to key names (not value) associated to a lease when `Keys` parameter is true, even a user doesn't have read permission to the keys. The impact is limited to a cluster which enables auth (RBAC). Versions 3.4.26 and 3.5.9 fix this issue. There are no known workarounds.

Authentication vulnerability found in Etcd-io v.3.4.10 allows remote attackers to escalate privileges via the debug function.

In etcd before versions 3.3.23 and 3.4.10, certain directory paths are created (etcd data directory and the directory path when provided to automatically generate self-signed certificates for TLS connections with clients) with restricted access permissions (700) by using the os.MkdirAll. This function does not perform any permission checks when a given directory path exists already. A possible workaround is to ensure the directories have the desired permission (700).

etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.