T09 · Insecure Skill Coding Practices
- Location
scripts/twenty-config.sh:11- Finding
Arbitrary Shell Execution Through Unsafe Configuration Loading
- Content
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Vulnerability Details
File Location:
scripts/twenty-config.sh:11, 29-31
Vulnerability Type: Executable configuration file / arbitrary shell command execution
Risk Level: MediumVulnerable Code
bash CONFIG_FILE="${TWENTY_CONFIG_FILE:-$DEFAULT_CONFIG_FILE}" if [ -f "$CONFIG_FILE" ]; then # shellcheck disable=SC1090 source "$CONFIG_FILE" fiTechnical Analysis
The script treats
config/twenty.envas a data-based environment file but loads it with Bash'ssourcebuilt-in. Sourcing a file executes its entire contents in the current shell rather than parsing only environment-variable assignments.Consequently, a configuration file can contain arbitrary shell commands, command substitutions, functions, redirections, or other Bash syntax. The
TWENTY_CONFIG_FILEenvironment variable also allows the caller to select any readable file as the configuration source.This becomes exploitable when an attacker can modify the default configuration file, influence
TWENTY_CONFIG_FILE, or otherwise cause a malicious file to be loaded. The injected commands execute with the same operating-system privileges and environment as the invoked CRM helper.Attack Path
- An attacker gains control over
config/twenty.envor influences the process environment to setTWENTY_CONFIG_FILEto an attacker-controlled readable file. - The attacker places shell commands in that file, potentially alongside valid
TWENTY_BASE_URLandTWENTY_API_KEYassignments. - A user or agent invokes any helper that sources
twenty-config.sh. twenty-config.shexecutessource "$CONFIG_FILE".- The attacker's commands run before the intended CRM API request and inherit the helper's privileges and environment.
Impact Assessment
Successful exploitation permits arbitrary command execution under the account running the Skill. The attacker could read files available to that account, access the configured Twenty CRM API key, alter local data, or mak ...[truncated 327 chars]
- An attacker gains control over
- Remediation
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Remediation Suggestions
Replace
sourcewith a non-executing configuration parser:- Accept only an explicit allowlist of keys, namely
TWENTY_BASE_URLandTWENTY_API_KEY. - Parse assignment lines as data without
eval,source, or shell expansion. - Reject command substitutions, shell operators, functions, redirections, unrecognized keys, and malformed lines.
- Prefer direct environment-variable configuration or a structured format parsed by a safe standard parser.
- If
TWENTY_CONFIG_FILEremains supported, resolve and validate the path and ensure that the file is a regular file owned by the expected user. - Reject configuration files writable by group or other users and recommend mode
0600. - Avoid exporting the API key unless child processes genuinely require it; pass secrets only to the specific command that needs them.
- Accept only an explicit allowlist of keys, namely