Merge pull request from GHSA-7rg2-cxvp-9p7p

* Fix authentication bypass if stored password hash is known Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu> * Add test for CVE-2022-46146 Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu> Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
prometheus · Nov 29, 2022 · 2528877 · 2528877
1 parent 48868f5
commit 2528877
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Showing 2 changed files with 56 additions and 2 deletions.
diff --git a/web/handler.go b/web/handler.go
@@ -19,6 +19,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"net/http"
+	"strings"
 	"sync"
 
 	"github.com/go-kit/log"
@@ -113,7 +114,12 @@ func (u *webHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			hashedPassword = "$2y$10$QOauhQNbBCuQDKes6eFzPeMqBSjb7Mr5DUmpZ/VcEd00UAV/LDeSi"
 		}
 
-		cacheKey := hex.EncodeToString(append(append([]byte(user), []byte(hashedPassword)...), []byte(pass)...))
+		cacheKey := strings.Join(
+			[]string{
+				hex.EncodeToString([]byte(user)),
+				hex.EncodeToString([]byte(hashedPassword)),
+				hex.EncodeToString([]byte(pass)),
+			}, ":")
 		authOk, ok := u.cache.get(cacheKey)
 
 		if !ok {
@@ -122,7 +128,7 @@ func (u *webHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			err := bcrypt.CompareHashAndPassword([]byte(hashedPassword), []byte(pass))
 			u.bcryptMtx.Unlock()
 
-			authOk = err == nil
+			authOk = validUser && err == nil
 			u.cache.set(cacheKey, authOk)
 		}
 

diff --git a/web/handler_test.go b/web/handler_test.go
@@ -129,6 +129,54 @@ func TestBasicAuthWithFakepassword(t *testing.T) {
 	login()
 }
 
+// TestByPassBasicAuthVuln tests for CVE-2022-46146.
+func TestByPassBasicAuthVuln(t *testing.T) {
+	server := &http.Server{
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Write([]byte("Hello World!"))
+		}),
+	}
+
+	done := make(chan struct{})
+	t.Cleanup(func() {
+		if err := server.Shutdown(context.Background()); err != nil {
+			t.Fatal(err)
+		}
+		<-done
+	})
+
+	go func() {
+		flags := FlagConfig{
+			WebListenAddresses: &([]string{port}),
+			WebSystemdSocket:   OfBool(false),
+			WebConfigFile:      OfString("testdata/web_config_users_noTLS.good.yml"),
+		}
+		ListenAndServe(server, &flags, testlogger)
+		close(done)
+	}()
+
+	login := func(username, password string) {
+		client := &http.Client{}
+		req, err := http.NewRequest("GET", "http://localhost"+port, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		req.SetBasicAuth(username, password)
+		r, err := client.Do(req)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if r.StatusCode != 401 {
+			t.Fatalf("bad return code, expected %d, got %d", 401, r.StatusCode)
+		}
+	}
+
+	// Poison the cache.
+	login("alice$2y$12$1DpfPeqF9HzHJt.EWswy1exHluGfbhnn3yXhR7Xes6m3WJqFg0Wby", "fakepassword")
+	// Login with a wrong password.
+	login("alice", "$2y$10$QOauhQNbBCuQDKes6eFzPeMqBSjb7Mr5DUmpZ/VcEd00UAV/LDeSifakepassword")
+}
+
 // TestHTTPHeaders validates that HTTP headers are added correctly.
 func TestHTTPHeaders(t *testing.T) {
 	server := &http.Server{