From: Cristy <urban-warrior@imagemagick.org>
Date: Thu, 15 Mar 2018 00:56:35 +0000 (-0400)
Subject: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6880
X-Git-Tag: 7.0.7-27~50
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=fc25040471ee40b11c5bdecb3b2efd5457c54022;p=imagemagick

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6880
---

diff --git a/coders/wpg.c b/coders/wpg.c
index d179f7e49..44749f945 100644
--- a/coders/wpg.c
+++ b/coders/wpg.c
@@ -1329,6 +1329,8 @@ static Image *ReadWPGImage(const ImageInfo *image_info,
               if ((WPG_Palette.NumOfEntries-WPG_Palette.StartIndex) >
                   (Rec2.RecordLength-2-2) / 3)
                 ThrowReaderException(CorruptImageError,"InvalidColormapIndex");
+              if (WPG_Palette.StartIndex >= WPG_Palette.NumOfEntries)
+                ThrowReaderException(CorruptImageError,"InvalidColormapIndex");
               image->colors=WPG_Palette.NumOfEntries;
               if (AcquireImageColormap(image,image->colors,exception) == MagickFalse)
                 ThrowReaderException(ResourceLimitError,