obs-service-extract_file's outfilename parameter allows to write files outside of package directory

Summary

Relative Path Traversal vulnerability in obs-service-tar_scm of SUSE Linux Enterprise Server 15; openSUSE Factory allows remote attackers with control over a repository to overwrite files on the machine of the local user if a malicious service is executed. This issue affects: SUSE Linux Enterprise Server 15 obs-service-tar_scm versions prior to 0.9.2.1537788075.fefaa74:. openSUSE Factory obs-service-tar_scm versions prior to 0.9.2.1537788075.fefaa74.