terraform-provider-proxmox has insecure sudo recommendation in the documentation
Date: 2026-02
Affected: go/github.com/bpg/terraform-provider-proxmox
Attack vector: path-traversal
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-25499
CWE: CWE-1188
CWE-22

> Note: It is uncertain whether this constitutes a vulnerability or should be filed as an issue instead. ### Summary In the SSH configuration documentation, the sudoer line that was suggested can be escalated to edit any files in the system. ### Details The following line were suggested for addition in the sudoers file: ```bash terraform ALL=(root) NOPASSWD: /usr/bin/tee /var/lib/vz/* ``` But this is highly insecure as the folder can be escaped using `../` and any files can be edited on the system. ### PoC Using a `terraform` user with the previously mentioned line in the `/etc/sudoers` file, a `/etc/sudoers.d/sudo` file can be added using this command: `echo "ALL=(ALL) NOPASSWD:ALL" | tee /var/lib/vz/../../../etc/sudoers.d/sudo` This grants access to the full root of the node. ### Impact This breaches the access limits of the Terraform user. ### Suggested workaround Use a strict regex on the command to allow only the names that should be pushed by this user. Example for cloudinit yaml files: ```bash terraform ALL=(root) NOPASSWD: /usr/bin/tee /var/lib/vz/snippets/[A-Za-z0-9-]*\\.yaml ```


Mitigations:

Architectural layers (MAESTRO):