← Signals
- docker
- container
- escape
- exploitarium
news
Docker cp Copy-Out Destination Escape
Container races host `docker cp` copy-out so extraction writes sibling path outside requested destination — validated on Engine 29.6.0.
Summary
Container races host docker cp copy-out so extraction writes sibling path outside requested destination — validated on Engine 29.6.0. This proof-of-concept is one of 30 folders in the Exploitarium collection. OFFSITE.DARK summarizes the upstream README and PoC design; we did not discover or weaponize this flaw.
Key Findings
| Finding | Detail |
|---|---|
| Product / target | Docker Client/Server 29.6.0 |
| Primitive | Tar stream extraction race against sibling prefix paths (dst vs dst2) |
| Impact | Container-controlled file write outside operator-selected host destination when copy-out races. |
Attack Chain
Host runs docker cp → container padding + raced path → marker under dst2/
Mitigation
Avoid copy-out from untrusted containers to sensitive host trees; isolate operator workflows.