diff --git a/device/bluetooth/bluetooth_service_record_win.cc b/device/bluetooth/bluetooth_service_record_win.cc
index 14936214a74c5..ed1dc6bea39ba 100644
--- a/device/bluetooth/bluetooth_service_record_win.cc
+++ b/device/bluetooth/bluetooth_service_record_win.cc
@@ -24,6 +24,15 @@ bool AdvanceToSdpType(const SDP_ELEMENT_DATA& sequence_data,
                       SDP_TYPE type,
                       HBLUETOOTH_CONTAINER_ELEMENT* element,
                       SDP_ELEMENT_DATA* sdp_data) {
+  // `data` is a union: `data.sequence.{value,length}` are only valid when the
+  // remote peer actually sent a container type. A malicious peer can encode
+  // attributes 0x0001 / 0x0004 as e.g. UINT128, in which case the 16 attacker
+  // bytes overlay the LPBYTE/ULONG pair and the call below would dereference
+  // an attacker-controlled pointer. Reject anything that is not a container.
+  if (sequence_data.type != SDP_TYPE_SEQUENCE &&
+      sequence_data.type != SDP_TYPE_ALTERNATIVE) {
+    return false;
+  }
   while (ERROR_SUCCESS == BluetoothSdpGetContainerElementData(
       sequence_data.data.sequence.value,
       sequence_data.data.sequence.length,