Fix CVE-2021-3405: A flaw was found in libebml before 1.4.2. A heap overflow bug exists in the implementation of EbmlString::ReadData and EbmlUnicodeString::ReadData in libebml. https://github.com/Matroska-Org/libebml/blob/release-1.4.2/ChangeLog Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com>