Null pointer dereference in Exiv2::Internal::resolveLens0x8ff

Exiv2 is a command-line utility and C++ library for reading, writing, deleting, and modifying the metadata of image files. A null pointer dereference was found in Exiv2 versions v0.27.4 and earlier. The null pointer dereference is triggered when Exiv2 is used to print the metadata of a crafted image file. An attacker could potentially exploit the vulnerability to cause a denial of service, if they can trick the victim into running Exiv2 on a crafted image file. Note that this bug is only triggered when printing the interpreted (translated) data, which is a less frequently used Exiv2 operation that requires an extra command line option (`-p t` or `-P t`). The bug is fixed in version v0.27.5.