It was found that GDCM versions 2.6.0 and 2.6.1 (and possibly previous versions) are prone to an integer overflow vulnerability which leads to a buffer overflow and potentially to remote code execution. The vulnerability is triggered by the exposed function gdcm::ImageRegionReader::ReadIntoBuffer, which copies DICOM image data to a buffer. ReadIntoBuffer checks whether the supplied buffer is large enough to hold the necessary data, however in this check it fails to detect the occurrence of an integer overflow, which leads to a buffer overflow later on in the code. The buffer overflow will occur regardless of the size of the buffer supplied to the ReadIntoBuffer call.

External reference:

http://census-labs.com/news/2016/01/11/gdcm-buffer-overflow-imageregionreaderreadintobuffer/