Exiv2 has quadratic performance in ICC profile parsing in JpegBase::readMetadata

Exiv2 is a C++ library and a command-line utility to read, write, delete and modify Exif, IPTC, XMP and ICC image metadata. A denial-of-service was found in Exiv2 version 0.28.5: a quadratic algorithm in the ICC profile parsing code in jpegBase::readMetadata() can cause Exiv2 to run for a long time. The denial-of-service is triggered when Exiv2 is used to read the metadata of a crafted jpg image file. The bug is fixed in version 0.28.6.