In sshd in OpenSSH through 10.6, in certain environments such as QNX 6 and SCO OpenServer 5, sshd-session can unexpectedly have root privileges. This is related to the GatewayPorts and StreamLocalForwarding configuration options, and lack of support for file-descriptor passing and unprivileged allocation of PTY devices.
Weakness
The elevated privilege level required to perform operations such as chroot() should be dropped immediately after the operation is performed.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openssh-ssh1 | Ubuntu | devel | * |
| Openssh-ssh1 | Ubuntu | esm-apps/bionic | * |
| Openssh-ssh1 | Ubuntu | esm-apps/focal | * |
| Openssh-ssh1 | Ubuntu | esm-apps/jammy | * |
| Openssh-ssh1 | Ubuntu | esm-apps/noble | * |
| Openssh-ssh1 | Ubuntu | esm-apps/resolute | * |
| Openssh-ssh1 | Ubuntu | jammy | * |
| Openssh-ssh1 | Ubuntu | noble | * |
| Openssh-ssh1 | Ubuntu | resolute | * |
| Openssh-ssh1 | Ubuntu | upstream | * |
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/35.html
- https://cwe.mitre.org/data/definitions/76.html