From e81f79ce9db5ff84186547372926eb3ee065effc Mon Sep 17 00:00:00 2001
From: Anil Mahtani <929854+Anilm3@users.noreply.github.com>
Date: Fri, 13 Oct 2023 15:23:38 +0100
Subject: [PATCH] Add check for null strings

---
 src/expression.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/expression.cpp b/src/expression.cpp
index 71a36e47a..bba38f772 100644
--- a/src/expression.cpp
+++ b/src/expression.cpp
@@ -5,6 +5,7 @@
 // Copyright 2021 Datadog, Inc.
 
 #include <charconv>
+#include <iostream>
 #include <memory>
 
 #include "exception.hpp"
@@ -50,7 +51,11 @@ std::optional<event::match> expression::evaluator::eval_object(const ddwaf_objec
 {
     ddwaf_object src = *object;
 
-    if (object->type == DDWAF_OBJ_STRING) {
+    if (src.type == DDWAF_OBJ_STRING) {
+        if (src.stringValue == nullptr) {
+            return std::nullopt;
+        }
+
         src.nbEntries = find_string_cutoff(src.stringValue, src.nbEntries, limits);
         if (!transformers.empty()) {
             ddwaf_object dst;