提交 #855869: louisho5 picobot 0.2.0 OS Command Injection (CWE-78)

# Technical Details
An OS command execution vulnerability exists in the `[ExecTool.Execute]` method in `internal/agent/tools/exec.go` of picobot.

The application fails to reject shell-wrapper payloads in array-form `exec` tool calls. `ExecTool.Execute` validates only `argv[0]` against a short dangerous-program blacklist and applies limited argument checks before passing the command to `exec.CommandContext`. A payload such as `["sh","-c","echo openclaw-shell-wrapper-bypass-canary > marker.txt"]` bypasses the intended restrictions and executes attacker-controlled shell syntax.

# Vulnerable Code
File: `internal/agent/tools/exec.go`
Method: `ExecTool.Execute`
Why: The code checks only the outer executable and does not inspect nested shell payloads supplied through `sh -c`, allowing arbitrary shell command execution.

# Reproduction
1. Build the Picobot binary and run a local OpenAI-compatible stub provider.
2. Return an `exec` tool call containing `["sh","-c","echo openclaw-shell-wrapper-bypass-canary > marker.txt"]`.
3. Run `picobot agent -m ...` and confirm that `marker.txt` is created with the expected canary content.

# Impact
- Permits arbitrary shell command execution as the Picobot OS user.
- Can expose secrets, alter files, and tamper with code or local infrastructure reachable by the process.

• 来源: ⚠️ https://github.com/louisho5/picobot/issues/42
• 用户: Eric-h (UID 97582)
• 提交: 2026-06-11 11時27分 (1 月前)
• 管理: 2026-07-13 23時12分 (1 month later)
• 状态: 已接受
• VulDB条目: 378163 [louisho5 picobot 直到 0.2.0 exec Tool exec.go ExecTool.Execute 权限提升]
• 积分: 20