CVE-2021-29463

Exiv2 is a command-line utility and C++ library for reading, writing,
deleting, and modifying the metadata of image files. An out-of-bounds read
was found in Exiv2 versions v0.27.3 and earlier. The out-of-bounds read is
triggered when Exiv2 is used to write metadata into a crafted image file.
An attacker could potentially exploit the vulnerability to cause a denial
of service by crashing Exiv2, if they can trick the victim into running
Exiv2 on a crafted image file. Note that this bug is only triggered when
writing the metadata, which is a less frequently used Exiv2 operation than
reading the metadata. For example, to trigger the bug in the Exiv2
command-line application, you need to add an extra command-line argument
such as insert. The bug is fixed in version v0.27.4.