On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, root.Open(symlink/) will open symlink even when symlink is a symbolic link pointing outside of the root.
Weakness
The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Go | Golang | * | 1.25.12 (excluding) |
| Go | Golang | 1.26.0 (including) | 1.26.5 (excluding) |
| Go | Golang | 1.27-rc1 (including) | 1.27-rc1 (including) |
| Red Hat Enterprise Linux 10 | RedHat | golang-0:1.26.5-1.el10_2 | * |
| Red Hat Enterprise Linux 10 | RedHat | buildah-2:1.43.1-4.el10_2 | * |
| Red Hat Enterprise Linux 8 | RedHat | go-toolset:rhel8-8100020260710105056.a3795dee | * |
| Red Hat Enterprise Linux 9 | RedHat | golang-0:1.26.5-1.el9_8 | * |
| Red Hat Enterprise Linux 9 | RedHat | buildah-2:1.43.1-4.el9_8 | * |
| Red Hat Enterprise Linux 9 | RedHat | podman-6:5.8.2-5.el9_8 | * |
| Red Hat Hardened Images | RedHat | golang1-26-main-1.26.5-0.1.hum1 | * |
| Red Hat Hardened Images | RedHat | golang1-25-main-1.25.12-0.1.hum1 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-gateway-opa-rhel9:1784775772 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-gateway-rhel9:1784775770 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-jaeger-query-rhel9:1784775834 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-operator-bundle:1784777166 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-query-rhel9:1784775793 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-rhel9:1784775768 | * |
| Red Hat OpenShift distributed tracing 3.10.2 | RedHat | rhosdt/tempo-rhel9-operator:1784775782 | * |
| Golang-1.23 | Ubuntu | questing | * |
| Golang-1.24 | Ubuntu | questing | * |
| Golang-1.25 | Ubuntu | questing | * |
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.