diff --git a/pkg/apis/core/validation/validation.go b/pkg/apis/core/validation/validation.go
index 686d184781f..61b543cc587 100644
--- a/pkg/apis/core/validation/validation.go
+++ b/pkg/apis/core/validation/validation.go
@@ -5450,24 +5450,32 @@ func ValidateService(service *core.Service) field.ErrorList {
 		ports[key] = true
 	}
 
-	// Validate SourceRange field and annotation
-	_, ok := service.Annotations[core.AnnotationLoadBalancerSourceRangesKey]
-	if len(service.Spec.LoadBalancerSourceRanges) > 0 || ok {
-		var fieldPath *field.Path
-		var val string
-		if len(service.Spec.LoadBalancerSourceRanges) > 0 {
-			fieldPath = specPath.Child("LoadBalancerSourceRanges")
-			val = fmt.Sprintf("%v", service.Spec.LoadBalancerSourceRanges)
-		} else {
-			fieldPath = field.NewPath("metadata", "annotations").Key(core.AnnotationLoadBalancerSourceRangesKey)
-			val = service.Annotations[core.AnnotationLoadBalancerSourceRangesKey]
-		}
+	// Validate SourceRanges field or annotation.
+	if len(service.Spec.LoadBalancerSourceRanges) > 0 {
+		fieldPath := specPath.Child("LoadBalancerSourceRanges")
+
 		if service.Spec.Type != core.ServiceTypeLoadBalancer {
 			allErrs = append(allErrs, field.Forbidden(fieldPath, "may only be used when `type` is 'LoadBalancer'"))
 		}
-		_, err := apiservice.GetLoadBalancerSourceRanges(service)
-		if err != nil {
-			allErrs = append(allErrs, field.Invalid(fieldPath, val, "must be a list of IP ranges. For example, 10.240.0.0/24,10.250.0.0/24 "))
+		for idx, value := range service.Spec.LoadBalancerSourceRanges {
+			// Note: due to a historical accident around transition from the
+			// annotation value, these values are allowed to be space-padded.
+			value = strings.TrimSpace(value)
+			allErrs = append(allErrs, validation.IsValidCIDR(fieldPath.Index(idx), value)...)
+		}
+	} else if val, annotationSet := service.Annotations[core.AnnotationLoadBalancerSourceRangesKey]; annotationSet {
+		fieldPath := field.NewPath("metadata", "annotations").Key(core.AnnotationLoadBalancerSourceRangesKey)
+		if service.Spec.Type != core.ServiceTypeLoadBalancer {
+			allErrs = append(allErrs, field.Forbidden(fieldPath, "may only be used when `type` is 'LoadBalancer'"))
+		}
+
+		val = strings.TrimSpace(val)
+		if val != "" {
+			cidrs := strings.Split(val, ",")
+			for _, value := range cidrs {
+				value = strings.TrimSpace(value)
+				allErrs = append(allErrs, validation.IsValidCIDR(fieldPath, value)...)
+			}
 		}
 	}