GHSA-v5r2-qh84-fjx5 Glances is Vulnerable to Command Injection via KVM/QEMU VM Domain Names in glances/plugins/vms/engines/virsh.py
SummaryThe Glances KVM/QEMU monitoring engine (`glances/plugins/vms/engines/virsh.py`) passes VM domain names, read directly from `virsh list --all` output, into f-string command templates that are processed by `secure_popen()`. `secure_popen()` is explicitly designed to interpret `&&`, `|`, and `>` as shell operators.  Because domain names are never sanitised before interpolation, any user with the ability to create or rename a KVM/QEMU virtual machine can execute arbitrary commands as the OS user running Glances — commonly root on hypervisor hosts.Details**Affected file:** `glances/plugins/vms/engines/virsh.py`**Direct URLs (commit 04579778e733d705898a169e049dc84772c852da):**https://github.com/nicolargo/glances/blob/04579778e733d705898a169e049dc84772c852da/glances/plugins/vms/engines/virsh.py#L185https://github.com/nicolargo/glances/blob/04579778e733d705898a169e049dc84772c852da/glances/plugins/vms/engines/virsh.py#L204The vulnerable calls are on lines 185 and 204:`domain` is the name string parsed from the output of `virsh list --all` (line 59–78 in the same file); no sanitisation is applied to it at  any point before it reaches `secure_popen()`.`secure_popen()` is defined in `glances/secure.py`.  It explicitly splits the command string on `&&`, `|`, and `>` before invoking `subprocess.Popen` with `shell=False` on each part, meaning all three operators are treated as real pipeline/redirection control characters:By contrast, `actions.py` sanitises process names through `_sanitize_mustache_dict()` before they reach `secure_popen()`.  The `vms` plugin applies no such protection.**Confirmed on:** x86_64 Linux, Python 3.13, Glances 4.5.5_dev1 (commit 04579778e733d705898a169e049dc84772c852da).All three injection operators were verified:| Operator | Effect | Confirmed |
|----------|--------|-----------|
| `&&`     | Second command executes after the virsh call | Yes |
| `\|`     | Output of virsh piped to injected command    | Yes |
| `>`      | virsh output redirected to arbitrary file    | Yes |PoC**Special configuration required**Glances must be configured to monitor a KVM/QEMU hypervisor: the `vms` plugin must be enabled and `/usr/bin/virsh` must be installed and executable.The attacker must have libvirt domain-creation or domain-rename privileges (e.g. membership in the `libvirt` group, a typical default on  Ubuntu/Debian/Fedora, or a cloud-platform tenant account).No custom `glances.conf` settings are needed beyond a working virsh setup.**Step 1 — Create a VM with a crafted domain name**Using the `&&` operator to chain a second command:**Step 2 — Start Glances with KVM monitoring enabled**On the next monitoring cycle Glances calls:which `secure_popen()` splits into two processes:`virsh domstats --nowait productionDB``touch /tmp/glances_pwned`**Step 3 — Verify execution****Pipe injection (`|`) example**Domain name: `"productionDB | tee /tmp/virsh_output_stolen.txt"`The output of the virsh call is piped to `tee`, writing the data to an attacker-controlled path.**File-write injection (`>`) example**Domain name: `"productionDB > /etc/cron.d/glances_backdoor"`The virsh output is redirected to a cron file, enabling persistent code execution on the next cron cycle.**Minimal Python reproduction (no VM required)**Impact**Vulnerability type:** Command Injection (CWE-78)**Who is impacted:** Any deployment of Glances on a KVM/QEMU hypervisor host where the `vms` plugin is active.  Exploitation requires the attacker to have libvirt domain-creation or domain-rename rights — a privilege granted by default to members of the `libvirt` group and to cloud-platform tenant APIs.**Impact:****Confidentiality:** Full — arbitrary commands can exfiltrate secrets from the Glances process environment and the file system.**Integrity:** Full — file-write injection (`>`) allows placing content in any file writable by the Glances process (cron, authorised_keys, etc.).**Availability:** Full — the Glances process can be terminated or the host disrupted through the injected commands.In cloud and multi-tenant virtualisation environments, Glances commonly runs as root on the hypervisor to access performance counters, so successful exploitation typically yields root-level code execution.Suggested FixReplace the f-string interpolation with list-based argument passing to avoid any interaction with `secure_popen()`'s operator splitting logic:Alternatively, sanitise `domain` using the same `_sanitize_mustache_dict` helper already used in `actions.py`, which strips `&&`, `|`, `>`, `;`, and backtick characters from string values.As a defence-in-depth measure, consider running Glances under a dedicated low-privilege service account with `CAP_SYS_PTRACE` rather than as root.Responsible DisclosureThe AFINE Team is committed to responsible / coordinated disclosure. The AFINE Team will not publish details of this vulnerability or release exploit code publicly until a fix has been released, or 90 days have elapsed from the date of this report, whichever comes first.CreditsThis issue was identified by Michał Majchrowicz and Marcin Wyczechowski, members
of the AFINE Team.
CVSS v3.1 score: 7.8