rubyzip gem rubyzip version 1.2.1 and earlier contains a Directory Traversal vulnerability in Zip::File component that can result in write arbitrary files to the filesystem. This attack appear to be exploitable via If a site allows uploading of .zip files , an attacker can upload a malicious file that contains symlinks or files with absolute pathnames "../" to write arbitrary files to the filesystem..

This is similar to CVE-2017-5946 which was patched in 1.2.1 but the fix in that case was incomplete.

References

• https://nvd.nist.gov/vuln/detail/CVE-2018-1000544
• rubyzip/rubyzip#369
• https://access.redhat.com/errata/RHSA-2018:3466
• https://lists.debian.org/debian-lts-announce/2018/08/msg00013.html
• https://lists.debian.org/debian-lts-announce/2020/08/msg00002.html
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rubyzip/CVE-2018-1000544.yml