Unarchive in pkg/utils/zip.go joined each archive entry name with the destination directory via filepath.Join and wrote the result without checking whether the resolved path stayed under the destination. A zip entry named
../../tmp/evil therefore landed at /tmp/evil. An attacker who could control a Package.Spec.Source.URL or Deployment.URL archive could induce the fetcher (running as the per-environment pod's fission-fetcher sidecar) to write
files anywhere that process could reach: into other tenants' /packages/<ns>/ directories, into mounted secret/config volumes, or into the fetcher's own binary.
github.com/fission/fission647c141pkg/utils/zip.go (Unarchive)Fix section (paste into the Fix / Patches field)
Fixed in v1.25.0 by:
55704aca) — Unarchive now opens an os.Root on the destination, validates each
archive entry name (rejects absolute paths and .. traversal), and refuses symlink entries up front. The os.Root confines every mkdir / create to the destination in the kernel.Regression coverage: TestUnarchiveZipSlip in pkg/utils/zip_test.go exercises parent-traversal, absolute-path, and symlink entries.
1.25.0Exploitability
AV:NAC:LPR:LUI:NScope
S:CImpact
C:NI:HA:N7.7/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:NInput Validation