Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:9 relevant versions.
The BEGIN regular expression in the awk script detector in magic/Magdir/commands in file before 5.15 uses multiple wildcards with unlimited repetitions, which allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted ASCII file that triggers a large amount of backtracking, as demonstrated via a file with many newline characters.
file to version 1:5.17-0.1 or higher.