From 85d566c0b1198ea3841ff8ba23f5dc95725b7144 Mon Sep 17 00:00:00 2001
From: Philippe Antoine <pantoine@oisf.net>
Date: Wed, 2 Oct 2024 20:39:26 +0200
Subject: [PATCH] transform/base64: check for 0-sized buffer

So as to avoid undefined behavior with a 0-sized variable length
array

Ticket: #7296
---
 src/detect-transform-base64.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/detect-transform-base64.c b/src/detect-transform-base64.c
index f8d8f6e241b..e0fbdeeb44d 100644
--- a/src/detect-transform-base64.c
+++ b/src/detect-transform-base64.c
@@ -141,6 +141,9 @@ static void TransformFromBase64Decode(InspectionBuffer *buffer, void *options)
         }
         decode_length = nbytes;
     }
+    if (decode_length == 0) {
+        return;
+    }
 
     uint32_t decoded_size = Base64DecodeBufferSize(decode_length);
     uint8_t decoded[decoded_size];