security: clear password after authenticating the user

server/etcdserver/v3_server.go

@@ -445,6 +445,13 @@ func (s *EtcdServer) Authenticate(ctx context.Context, r *pb.AuthenticateRequest
 
 	lg := s.Logger()
 
+	// fix https://nvd.nist.gov/vuln/detail/CVE-2021-28235
+	defer func() {
+		if r != nil {
+			r.Password = ""
+		}
+	}()
+
 	var resp proto.Message
 	for {
 		checkedRevision, err := s.AuthStore().CheckPassword(r.Name, r.Password)

tests/e2e/cmux_test.go

@@ -208,12 +208,3 @@ func fetchDebugVars(endpoint string, httpVersion string, connType e2e.ClientConn
 	var resp map[string]interface{}
 	return json.Unmarshal([]byte(respData), &resp)
 }
-
-func curl(endpoint string, method string, curlReq e2e.CURLReq, connType e2e.ClientConnType) (string, error) {
-	args := e2e.CURLPrefixArgs(endpoint, e2e.ClientConfig{ConnectionType: connType}, false, method, curlReq)
-	lines, err := e2e.RunUtilCompletion(args, nil)
-	if err != nil {
-		return "", err
-	}
-	return strings.Join(lines, "\n"), nil
-}

tests/e2e/ctl_v3_auth_security_test.go

@@ -0,0 +1,57 @@
+// Copyright 2023 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !cluster_proxy
+
+package e2e
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.etcd.io/etcd/tests/v3/framework/e2e"
+)
+
+// TestAuth_CVE_2021_28235 verifies https://nvd.nist.gov/vuln/detail/CVE-2021-28235
+func TestAuth_CVE_2021_28235(t *testing.T) {
+	testCtl(t, authTest_CVE_2021_28235, withCfg(*e2e.NewConfigNoTLS()), withLogLevel("debug"))
+}
+
+func authTest_CVE_2021_28235(cx ctlCtx) {
+	// create root user with root role
+	rootPass := "changeme123"
+	err := ctlV3User(cx, []string{"add", "root", "--interactive=false"}, "User root created", []string{rootPass})
+	require.NoError(cx.t, err)
+	err = ctlV3User(cx, []string{"grant-role", "root", "root"}, "Role root is granted to user root", nil)
+	require.NoError(cx.t, err)
+	err = ctlV3AuthEnable(cx)
+	require.NoError(cx.t, err)
+
+	// issue a put request
+	cx.user, cx.pass = "root", rootPass
+	err = ctlV3Put(cx, "foo", "bar", "")
+	require.NoError(cx.t, err)
+
+	// GET /debug/requests
+	httpEndpoint := cx.epc.Procs[0].EndpointsHTTP()[0]
+	req := e2e.CURLReq{Endpoint: "/debug/requests?fam=grpc.Recv.etcdserverpb.Auth&b=0&exp=1", Timeout: 5}
+	respData, err := curl(httpEndpoint, "GET", req, e2e.ClientNonTLS)
+	require.NoError(cx.t, err)
+
+	if strings.Contains(respData, rootPass) {
+		cx.t.Errorf("The root password is included in the request.\n %s", respData)
+	}
+}

tests/e2e/ctl_v3_test.go

@@ -202,6 +202,12 @@ func withMaxConcurrentStreams(streams uint32) ctlOption {
 	}
 }
 
+func withLogLevel(logLevel string) ctlOption {
+	return func(cx *ctlCtx) {
+		cx.cfg.LogLevel = logLevel
+	}
+}
+
 func testCtl(t *testing.T, testFunc func(ctlCtx), opts ...ctlOption) {
 	testCtlWithOffline(t, testFunc, nil, opts...)
 }

tests/e2e/utils.go

@@ -17,6 +17,7 @@ package e2e
 import (
 	"context"
 	"fmt"
+	"strings"
 	"testing"
 	"time"
 
@@ -97,3 +98,12 @@ func fillEtcdWithData(ctx context.Context, c *clientv3.Client, dbSize int) error
 	}
 	return g.Wait()
 }
+
+func curl(endpoint string, method string, curlReq e2e.CURLReq, connType e2e.ClientConnType) (string, error) {
+	args := e2e.CURLPrefixArgs(endpoint, e2e.ClientConfig{ConnectionType: connType}, false, method, curlReq)
+	lines, err := e2e.RunUtilCompletion(args, nil)
+	if err != nil {
+		return "", err
+	}
+	return strings.Join(lines, "\n"), nil
+}