CVE-2022-30708 (published 2022-05-15T03:15Z)

Webmin through 1.991, when the Authentic theme is used, allows remote code execution when a user has been manually created (i.e., not created in Virtualmin or Cloudmin). This occurs because settings-editor_write.cgi does not properly restrict the file parameter.

Severity: MEDIUM
CVSS v2 base score: 6.5 (AV:N/AC:L/Au:S/C:P/I:P/A:P)
CVSS v3 base score: 8.8, HIGH (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: NVD-CWE-noinfo
cwe_name: Insufficient Information
description: There is insufficient information about the issue to classify it; details are unkown or unspecified.
extended_description: Insufficient Information

Fix information:
repo_url: https://github.com/webmin/webmin
commit_details: repo_url: https://github.com/webmin/webmin
author: Jamie Cameron
author_date: 2022-05-14 11:38:03-07:00
msg: Factor out check for root-ish user into a separate function https://github.com/webmin/webmin/issues/1635
repository: repo_url: https://github.com/webmin/webmin
repo_name: webmin/webmin
description: Powerful and flexible web-based server management control panel
repo_language: HTML
owner: webmin
file_changes: filename: WebminCore.pm
change_type: ModificationType.MODIFY
diff: @@ -20,7 +20,7 @@ require Exporter;
 # Add functions in web-lib-funcs.pl
 # Generated with :
 # grep -h "^sub " web-lib-funcs.pl ui-lib.pl | sed -e 's/sub //' | xargs echo
-@EXPORT = qw(read_file read_file_cached read_file_cached_with_stat write_file html_escape html_strip quote_escape quote_javascript tempname_dir tempname transname transname_timestamped trunc indexof indexoflc sysprint check_ipaddress check_ip6address generate_icon urlize un_urlize include copydata ReadParseMime ReadParse read_fully read_parse_mime_callback read_parse_mime_javascript PrintHeader header get_html_title get_html_framed_title get_html_status_line popup_header footer popup_footer load_module_preferences load_theme_library redirect kill_byname kill_byname_logged find_byname error popup_error register_error_handler call_error_handlers error_setup wait_for fast_wait_for has_command make_date file_chooser_button popup_window_button popup_window_link read_acl acl_filename acl_check get_miniserv_config_file get_miniserv_config put_miniserv_config restart_miniserv reload_miniserv check_os_support http_download complete_http_download http_post ftp_download ftp_upload no_proxy open_socket download_timeout ftp_command to_ipaddress to_ip6address to_hostname icons_table replace_meta replace_file_line read_file_lines flush_file_lines unflush_file_lines unix_user_input unix_group_input hlink user_chooser_button group_chooser_button foreign_check foreign_exists foreign_func_exists foreign_available foreign_require foreign_call foreign_config foreign_installed foreign_defined get_system_hostname get_webmin_version get_webmin_version_release get_module_acl get_group_module_acl save_module_acl save_group_module_acl init_config load_language_auto load_language text_subs text encode_base64 decode_base64 encode_base32 decode_base32 get_module_info get_all_module_infos list_themes get_theme_info list_languages safe_language read_env_file write_env_file lock_file unlock_file test_lock unlock_all_files can_lock_file webmin_log additional_log var_dump webmin_debug_log system_logged backquote_logged backquote_with_timeout backquote_command kill_logged rename_logged rename_file symlink_logged symlink_file link_file make_dir set_ownership_permissions unlink_logged unlink_file copy_source_dest move_source_dest remote_session_name remote_foreign_require remote_foreign_call remote_foreign_check remote_foreign_config remote_eval remote_write remote_read remote_finished remote_error_setup remote_rpc_call remote_multi_callback remote_multi_callback_error serialise_variable unserialise_variable other_groups date_chooser_button help_file seed_random disk_usage_kb recursive_disk_usage help_search_link make_http_connection validate_ssl_connection read_http_connection write_http_connection close_http_connection clean_environment reset_environment clean_language progress_callback switch_to_remote_user switch_to_unix_user eval_as_unix_user create_user_config_dirs create_missing_homedir filter_javascript resolve_links simplify_path same_file flush_webmin_caches list_usermods available_usermods get_available_module_infos get_visible_module_infos get_visible_modules_categories is_under_directory parse_http_url check_clicks_function load_entities_map entities_to_ascii get_product_name get_charset get_display_hostname save_module_config save_user_module_config nice_size get_perl_path get_goto_module select_all_link select_invert_link select_rows_link check_pid_file get_mod_lib module_root_directory list_mime_types guess_mime_type open_tempfile close_tempfile print_tempfile is_selinux_enabled get_clear_file_attributes reset_file_attributes cleanup_tempnames open_lock_tempfile END month_to_number number_to_month get_rbac_module_acl supports_rbac supports_ipv6 use_rbac_module_acl execute_command open_readfile open_execute_command translate_filename translate_command register_filename_callback register_command_callback capture_function_output capture_function_output_tempfile modules_chooser_button substitute_template substitute_pattern running_in_zone running_in_vserver running_in_xen running_in_openvz list_categories is_readonly_mode command_as_user list_osdn_mirrors convert_osdn_url get_current_dir supports_users supports_symlinks quote_path get_windows_root read_file_contents write_file_contents read_file_contents_limit unix_crypt split_quoted_string write_to_http_cache check_in_http_cache supports_javascript get_module_name get_module_variable clear_time_locale reset_time_locale callers_package web_libs_package get_userdb_string connect_userdb disconnect_userdb split_userdb_string uniquelc list_combined_webmin_menu list_modules_webmin_menu module_to_menu_item list_combined_system_info shell_is_bash compare_version_numbers convert_to_json convert_from_json print_json get_referer_relative get_webmin_email_url get_webmin_browser_url trim ui_link ui_help ui_img ui_link_button ui_table_start ui_table_end ui_table_row ui_table_hr ui_table_span ui_columns_start ui_columns_row ui_columns_header ui_checked_columns_row ui_radio_columns_row ui_columns_end ui_columns_table ui_form_columns_table ui_form_start ui_form_end ui_textbox ui_filebox ui_bytesbox ui_upload ui_password ui_hidden ui_select ui_multi_select ui_multi_select_javascript ui_radio ui_yesno_radio ui_checkbox ui_oneradio ui_textarea ui_user_textbox ui_users_textbox ui_group_textbox ui_groups_textbox ui_opt_textbox ui_submit ui_reset ui_button ui_date_input ui_buttons_start ui_buttons_end ui_buttons_row ui_buttons_hr ui_post_header ui_pre_footer ui_print_header ui_print_unbuffered_header ui_print_footer ui_config_link ui_print_endpage ui_subheading ui_links_row ui_hidden_javascript ui_hidden_start ui_hidden_end ui_hidden_table_row_start ui_hidden_table_row_end ui_hidden_table_start ui_hidden_table_end ui_tabs_start ui_tabs_end ui_tabs_start_tab ui_tabs_start_tabletab ui_tabs_end_tab ui_tabs_end_tabletab ui_max_text_width ui_radio_selector ui_radio_selector_javascript ui_grid_table ui_radio_table ui_up_down_arrows ui_hr ui_nav_link ui_confirmation_form ui_text_color ui_alert_box js_disable_inputs ui_page_flipper js_checkbox_disable js_redirect ui_webmin_link ui_line_break_double ui_details ui_read_file_contents_limit get_python_cmd get_buffer_size get_webprefix get_sub_ref_name setvar getvar delvar print_call_stack);
+@EXPORT = qw(read_file read_file_cached read_file_cached_with_stat write_file html_escape html_strip quote_escape quote_javascript tempname_dir tempname transname transname_timestamped trunc indexof indexoflc sysprint check_ipaddress check_ip6address generate_icon urlize un_urlize include copydata ReadParseMime ReadParse read_fully read_parse_mime_callback read_parse_mime_javascript PrintHeader header get_html_title get_html_framed_title get_html_status_line popup_header footer popup_footer load_module_preferences load_theme_library redirect kill_byname kill_byname_logged find_byname error popup_error register_error_handler call_error_handlers error_setup wait_for fast_wait_for has_command make_date file_chooser_button popup_window_button popup_window_link read_acl acl_filename acl_check get_miniserv_config_file get_miniserv_config put_miniserv_config restart_miniserv reload_miniserv check_os_support http_download complete_http_download http_post ftp_download ftp_upload no_proxy open_socket download_timeout ftp_command to_ipaddress to_ip6address to_hostname icons_table replace_meta replace_file_line read_file_lines flush_file_lines unflush_file_lines unix_user_input unix_group_input hlink user_chooser_button group_chooser_button foreign_check foreign_exists foreign_func_exists foreign_available foreign_require foreign_call foreign_config foreign_installed foreign_defined get_system_hostname get_webmin_version get_webmin_version_release get_module_acl get_group_module_acl save_module_acl save_group_module_acl init_config load_language_auto load_language text_subs text encode_base64 decode_base64 encode_base32 decode_base32 get_module_info get_all_module_infos list_themes get_theme_info list_languages safe_language read_env_file write_env_file lock_file unlock_file test_lock unlock_all_files can_lock_file webmin_log additional_log var_dump webmin_debug_log system_logged backquote_logged backquote_with_timeout backquote_command kill_logged rename_logged rename_file symlink_logged symlink_file link_file make_dir set_ownership_permissions unlink_logged unlink_file copy_source_dest move_source_dest remote_session_name remote_foreign_require remote_foreign_call remote_foreign_check remote_foreign_config remote_eval remote_write remote_read remote_finished remote_error_setup remote_rpc_call remote_multi_callback remote_multi_callback_error serialise_variable unserialise_variable other_groups date_chooser_button help_file seed_random disk_usage_kb recursive_disk_usage help_search_link make_http_connection validate_ssl_connection read_http_connection write_http_connection close_http_connection clean_environment reset_environment clean_language progress_callback switch_to_remote_user switch_to_unix_user eval_as_unix_user create_user_config_dirs create_missing_homedir filter_javascript resolve_links simplify_path same_file flush_webmin_caches list_usermods available_usermods get_available_module_infos get_visible_module_infos get_visible_modules_categories is_under_directory parse_http_url check_clicks_function load_entities_map entities_to_ascii get_product_name get_charset get_display_hostname save_module_config save_user_module_config nice_size get_perl_path get_goto_module select_all_link select_invert_link select_rows_link check_pid_file get_mod_lib module_root_directory list_mime_types guess_mime_type open_tempfile close_tempfile print_tempfile is_selinux_enabled get_clear_file_attributes reset_file_attributes cleanup_tempnames open_lock_tempfile END month_to_number number_to_month get_rbac_module_acl supports_rbac supports_ipv6 use_rbac_module_acl execute_command open_readfile open_execute_command translate_filename translate_command register_filename_callback register_command_callback capture_function_output capture_function_output_tempfile modules_chooser_button substitute_template substitute_pattern running_in_zone running_in_vserver running_in_xen running_in_openvz list_categories is_readonly_mode command_as_user list_osdn_mirrors convert_osdn_url get_current_dir supports_users supports_symlinks quote_path get_windows_root read_file_contents write_file_contents read_file_contents_limit unix_crypt split_quoted_string write_to_http_cache check_in_http_cache supports_javascript get_module_name get_module_variable clear_time_locale reset_time_locale callers_package web_libs_package get_userdb_string connect_userdb disconnect_userdb split_userdb_string uniquelc list_combined_webmin_menu list_modules_webmin_menu module_to_menu_item list_combined_system_info shell_is_bash compare_version_numbers convert_to_json convert_from_json print_json get_referer_relative get_webmin_email_url get_webmin_browser_url trim ui_link ui_help ui_img ui_link_button ui_table_start ui_table_end ui_table_row ui_table_hr ui_table_span ui_columns_start ui_columns_row ui_columns_header ui_checked_columns_row ui_radio_columns_row ui_columns_end ui_columns_table ui_form_columns_table ui_form_start ui_form_end ui_textbox ui_filebox ui_bytesbox ui_upload ui_password ui_hidden ui_select ui_multi_select ui_multi_select_javascript ui_radio ui_yesno_radio ui_checkbox ui_oneradio ui_textarea ui_user_textbox ui_users_textbox ui_group_textbox ui_groups_textbox ui_opt_textbox ui_submit ui_reset ui_button ui_date_input ui_buttons_start ui_buttons_end ui_buttons_row ui_buttons_hr ui_post_header ui_pre_footer ui_print_header ui_print_unbuffered_header ui_print_footer ui_config_link ui_print_endpage ui_subheading ui_links_row ui_hidden_javascript ui_hidden_start ui_hidden_end ui_hidden_table_row_start ui_hidden_table_row_end ui_hidden_table_start ui_hidden_table_end ui_tabs_start ui_tabs_end ui_tabs_start_tab ui_tabs_start_tabletab ui_tabs_end_tab ui_tabs_end_tabletab ui_max_text_width ui_radio_selector ui_radio_selector_javascript ui_grid_table ui_radio_table ui_up_down_arrows ui_hr ui_nav_link ui_confirmation_form ui_text_color ui_alert_box js_disable_inputs ui_page_flipper js_checkbox_disable js_redirect ui_webmin_link ui_line_break_double ui_details ui_read_file_contents_limit get_python_cmd get_buffer_size get_webprefix get_sub_ref_name setvar getvar delvar print_call_stack webmin_user_is_admin);
 
 # Add global variables in web-lib.pl
 push(@EXPORT, qw(&unique));

programming_language: Ruby
filename: fastrpc.cgi
change_type: ModificationType.MODIFY
diff: @@ -13,10 +13,7 @@ $force_lang = $default_lang;
 print "Content-type: text/plain\n\n";
 
 # Can this user make remote calls?
-%access = &get_module_acl();
-if ($access{'rpc'} == 0 || $access{'rpc'} == 2 &&
-    $base_remote_user ne 'admin' && $base_remote_user ne 'root' &&
-    $base_remote_user ne 'sysadm') {
+if (!&webmin_user_is_admin()) {
 	print "0 Invalid user for RPC\n";
 	exit;
 	}

programming_language: Perl
filename: rpc.cgi
change_type: ModificationType.MODIFY
diff: @@ -27,10 +27,7 @@ $| = 1;
 print "Content-type: text/plain\n\n";
 
 # Can this user make remote calls?
-%access = &get_module_acl();
-if ($access{'rpc'} == 0 || $access{'rpc'} == 2 &&
-    $base_remote_user ne 'admin' && $base_remote_user ne 'root' &&
-    $base_remote_user ne 'sysadm') {
+if (!&webmin_user_is_admin()) {
 	print &serialise_variable( { 'status' => 0 } );
 	exit;
 	}

programming_language: Perl
filename: web-lib-funcs.pl
change_type: ModificationType.MODIFY
diff: @@ -12118,6 +12118,20 @@ my ($variable, $scope) = @_;
 return &globals('delete', $variable, $scope);
 }
 
+# webmin_user_is_admin([username])
+# Returns 1 if the given user should be considered fully trusted
+sub webmin_user_is_admin
+{
+my ($user) = @_;
+$user ||= $base_remote_user;
+my %access = &get_module_acl($user, "");
+return 1 if ($access{'rpc'} == 0);	# Can make arbitary RPC calls
+return 0 if ($access{'rpc'} == 1);	# Cannot make RPCs
+
+# Assume that standard admin usernames are root-capable as a fallback
+return $user eq 'admin' || $user eq 'root' || $user eq 'sysadm';
+}
+
 $done_web_lib_funcs = 1;
 
 1;

programming_language: Perl