CodeWhale: exec_shell_interact sends LLM-controlled input to a running shell without an approval prompt (privilege escalation)

Maintainer resolution

The CodeWhale maintainers validated this report. The affected package ranges are recorded in the advisory metadata. Version 0.8.64 contains the fix in commit 57f3c89471e27ac4032d9791f6885e5d4408c381. Users should upgrade to 0.8.64 or later. The original reporter analysis is preserved below.

Summary

exec_shell is correctly approval-gated. Its sibling exec_shell_interact returns ApprovalRequirement::Auto, so when the model writes input into a shell the user already approved (a python3 -i REPL, mysql, ssh, sudo -i, etc.), no prompt fires. Inside those processes, "stdin" is the command surface, so the model gets to run commands at whatever privilege that process holds. The user approved opening the shell once, for a stated purpose; the input that then runs in it is chosen by the model, and can be steered by any prompt injection the agent ingests afterward.

Details

The vulnerability requires two ordinary preconditions: shell tools are enabled (the normal config for using CodeWhale as a coding agent), and the session already has one approved long-running interactive process. After that, any untrusted content the agent reads can drive a exec_shell_interact call.

crates/tui/src/tools/shell.rs:2834-2910:

fn capabilities(&self) -> Vec<ToolCapability> {
    vec![ToolCapability::ExecutesCode]
}

fn approval_requirement(&self) -> ApprovalRequirement {
    ApprovalRequirement::Auto          // overrides the Required-for-ExecutesCode default
}

async fn execute(&self, input: Value, context: &ToolContext) -> Result<ToolResult, ToolError> {
    let task_id = required_task_id(&input)?;
    let close_stdin = optional_bool(&input, "close_stdin", false);
    let interaction_input = input
        .get("input").or_else(|| input.get("stdin")).or_else(|| input.get("data"))  // LLM-controlled
        .and_then(serde_json::Value::as_str).unwrap_or("");
    {
        let mut manager = context.shell_manager.lock()...;
        if !interaction_input.is_empty() || close_stdin {
            manager.write_stdin(task_id, interaction_input, close_stdin)...;          // no prompt
        }
    }
    ...
}