Affected: Homebrew: glances

Glances is an open-source system cross-platform monitoring tool. The Glances action system allows administrators to configure shell commands that execute when monitoring thresholds are exceeded. These commands support Mustache template variables (e.g., `{{name}}`, `{{key}}`) that are populated with runtime monitoring data. The `secure_popen()` function, which executes these commands, implements its own pipe, redirect, and chain operator handling by splitting the command string before passing each segment to `subprocess.Popen(shell=False)`. Prior to 4.5.2, when a Mustache-rendered value (such as a process name, filesystem mount point, or container name) contains pipe, redirect, or chain metacharacters, the rendered command is split in unintended ways, allowing an attacker who controls a process name or container name to inject arbitrary commands. Version 4.5.2 fixes the issue.

Glances is an open-source system cross-platform monitoring tool. The Glances action system allows administrators to configure shell commands that execute when monitoring thresholds are exceeded. These commands support Mustache template variables (e.g., `{{name}}`, `{{key}}`) that are populated with runtime monitoring data. The `secure_popen()` function, which executes these commands, implements its own pipe, redirect, and chain operator handling by splitting the command string before passing each segment to `subprocess.Popen(shell=False)`. Prior to 4.5.2, when a Mustache-rendered value (such as a process name, filesystem mount point, or container name) contains pipe, redirect, or chain metacharacters, the rendered command is split in unintended ways, allowing an attacker who controls a process name or container name to inject arbitrary commands. Version 4.5.2 fixes the issue.

Affected: PyPI: Glances

## Summary

The Glances action system allows administrators to configure shell commands that execute when monitoring thresholds are exceeded. These commands support Mustache template variables (e.g., `{{name}}`, `{{key}}`) that are populated with runtime monitoring data. The `secure_popen()` function, which executes these commands, implements its own pipe, redirect, and chain operator handling by splitting the command string before passing each segment to `subprocess.Popen(shell=False)`. When a Mustache-rendered value (such as a process name, filesystem mount point, or container name) contains pipe, redirect, or chain metacharacters, the rendered command is split in unintended ways, allowing an attacker who controls a process name or container name to inject arbitrary commands.

## Details

**The action execution flow:**

1. Admin configures an action in glances.conf (documented feature):

```ini [cpu] critical_action=echo "High CPU on {{name}}" | mail admin@example.com ```

2. When the threshold is exceeded, the plugin model renders the template with runtime stats (glances/plugins/plugin/model.py:943):

```python self.actions.run(stat_name, trigger, command, repeat, mustache_dict=mustache_dict) ```

3. The mustache_dict contains the full stat dictionary, including user-controllable fields like process name, filesystem mnt_point, container name, etc. (glances/plugins/plugin/model.py:920-943).

4. In glances/actions.py:77-78, the Mustache library renders the template:

```pyt…

glances-common-4.5.2-1.1 on GA media

Affected: PyPI: glances

Glances is an open-source system cross-platform monitoring tool. The Glances action system allows administrators to configure shell commands that execute when monitoring thresholds are exceeded. These commands support Mustache template variables (e.g., `{{name}}`, `{{key}}`) that are populated with runtime monitoring data. The `secure_popen()` function, which executes these commands, implements its own pipe, redirect, and chain operator handling by splitting the command string before passing each segment to `subprocess.Popen(shell=False)`. Prior to 4.5.2, when a Mustache-rendered value (such as a process name, filesystem mount point, or container name) contains pipe, redirect, or chain metacharacters, the rendered command is split in unintended ways, allowing an attacker who controls a process name or container name to inject arbitrary commands. Version 4.5.2 fixes the issue.

Affected: Ubuntu:Pro:16.04:LTS: glances, Ubuntu:Pro:18.04:LTS: glances, Ubuntu:Pro:20.04:LTS: glances, Ubuntu:22.04:LTS: glances, Ubuntu:24.04:LTS: glances, Ubuntu:25.10: glances, Ubuntu:26.04:LTS: glances

Glances is an open-source system cross-platform monitoring tool. The Glances action system allows administrators to configure shell commands that execute when monitoring thresholds are exceeded. These commands support Mustache template variables (e.g., `{{name}}`, `{{key}}`) that are populated with runtime monitoring data. The `secure_popen()` function, which executes these commands, implements its own pipe, redirect, and chain operator handling by splitting the command string before passing each segment to `subprocess.Popen(shell=False)`. Prior to 4.5.2, when a Mustache-rendered value (such as a process name, filesystem mount point, or container name) contains pipe, redirect, or chain metacharacters, the rendered command is split in unintended ways, allowing an attacker who controls a process name or container name to inject arbitrary commands. Version 4.5.2 fixes the issue.