zrok copy writes attacker-controlled WebDAV paths outside the destination root

## Summary Alice runs `zrok2 copy` from a WebDAV or zrok drive controlled by Bob into a local filesystem target. Bob returns a DAV `href` such as `/../outside.txt`. The sync pipeline stores that path in the source inventory and passes it to `FilesystemTarget.WriteStream`, which joins it with the target root and creates the file outside Alice's selected directory. ### Impact Users given access to a zrok share may be able to traverse the directory tree arbitrarily with the sharing users credentials, allowing for sensitive information to be overwritten.

Source published

19 May 2026 15:38:56 UTC

Source modified

25 Jun 2026 19:56:36 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N

Publisher rating · HIGH