hostapd_cli: Use os_exec() for action script execution

Use os_exec() to run the action script operations to avoid undesired
command line processing for control interface event strings. Previously,
it could have been possible for some of the event strings to include
unsanitized data which is not suitable for system() use. (CVE-2014-3686)

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

hostapd/hostapd_cli.c

@@ -238,28 +238,19 @@ static int hostapd_cli_cmd_mib(struct wpa_ctrl *ctrl, int argc, char *argv[])
 static int hostapd_cli_exec(const char *program, const char *arg1,
 			    const char *arg2)
 {
-	char *cmd;
+	char *arg;
 	size_t len;
 	int res;
-	int ret = 0;
 
-	len = os_strlen(program) + os_strlen(arg1) + os_strlen(arg2) + 3;
-	cmd = os_malloc(len);
-	if (cmd == NULL)
+	len = os_strlen(arg1) + os_strlen(arg2) + 2;
+	arg = os_malloc(len);
+	if (arg == NULL)
 		return -1;
-	res = os_snprintf(cmd, len, "%s %s %s", program, arg1, arg2);
-	if (res < 0 || (size_t) res >= len) {
-		os_free(cmd);
-		return -1;
-	}
-	cmd[len - 1] = '\0';
-#ifndef _WIN32_WCE
-	if (system(cmd) < 0)
-		ret = -1;
-#endif /* _WIN32_WCE */
-	os_free(cmd);
+	os_snprintf(arg, len, "%s %s", arg1, arg2);
+	res = os_exec(program, arg, 1);
+	os_free(arg);
 
-	return ret;
+	return res;
 }