An issue was discovered in Podman in libpod before 1.6.0. It resolves a symlink in the host context during a copy operation from the container to the host, because an undesired glob operation occurs. An attacker could create a container image containing particular symlinks that, when copied by a victim user to the host filesystem, may overwrite existing files with others from the host.
Weakness
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libpod | Libpod_project | * | 1.6.0 (excluding) |
| Red Hat Enterprise Linux 7 Extras | RedHat | podman-0:1.6.4-16.el7_8 | * |
| Red Hat Enterprise Linux 8 | RedHat | container-tools:rhel8-8010020191126140055.c294d161 | * |
Potential Mitigations
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/132.html
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/35.html
- https://cwe.mitre.org/data/definitions/76.html
References
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00040.html
- https://access.redhat.com/errata/RHSA-2019:4269
- https://bugzilla.redhat.com/show_bug.cgi?id=1744588
- https://github.com/containers/libpod/commit/5c09c4d2947a759724f9d5aef6bac04317e03f7e
- https://github.com/containers/libpod/compare/v1.5.1...v1.6.0
- https://github.com/containers/libpod/issues/3829
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00040.html
- https://access.redhat.com/errata/RHSA-2019:4269
- https://bugzilla.redhat.com/show_bug.cgi?id=1744588
- https://github.com/containers/libpod/commit/5c09c4d2947a759724f9d5aef6bac04317e03f7e
- https://github.com/containers/libpod/compare/v1.5.1...v1.6.0
- https://github.com/containers/libpod/issues/3829