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HTML-FormHandler-0.40068
⭐ Starred 89 / HTML::FormHandler::Render::RepeatableJs
Security Advisories (1)
CVE-2022-4993 (2026-08-13)

HTML::FormHandler versions through 0.40068 for Perl allow attacker selected method dispatch and resource exhaustion because _apply_actions and add_error use error message text built from request data as a Locale::Maketext bracket notation template. add_error hands its first argument to the language handle as the Locale::Maketext message key, and the default handle's lexicon sets `_AUTO`, so a string that is not a lexicon entry is compiled as a bracket notation template instead of being looked up. In a bracket group the first token names a method called on the language handle and the remaining tokens are its arguments. Three kinds of text the library did not author reach that position. _apply_actions installs a `$SIG{__WARN__}` handler that stores the warning text in `$error_message`, and a captured warning survives a successful action, so a field carrying a numeric transform turns `Argument "[sprintf,%50000000d,0]" isn't numeric` into the template; a warning quotes the submitted value verbatim, so the group is well formed and dispatches. `$error_message ||= $tobj->validate($new_value)` takes a type constraint's own failure message, which renders the rejected value through a partial dumper in bracket and comma form (Devel::PartialDump when Moose can load it, Type::Tiny's own dumper always), so a field with `apply => [ Str ]` given a parameter sent more than once, which arrives as an array, gets `Reference ["a","b"] did not pass type constraint "Str"` as its template, from a request that carries no bracket character of its own. A coercion or transform exception reaches it the same way. Beyond those, a validator whose message contains the field value puts that value in the template directly, and add_error replaces the message list with the contents of an arrayref first argument (`@message = @{$message[0]} if ref $message[0] eq 'ARRAY'`), so a value arriving as an array fills the argument slots from the same request as well. A malformed group such as `[0]` makes the compile croak, and HTML::FormHandler::I18N::maketext and add_error each re-raise that as a die, so process() throws. A well formed group naming sprintf reaches CORE::sprintf with an attacker chosen field width. Any caller that applies a type constraint or a transform to an untrusted field, or whose validator passes an untrusted field value to add_error, can be made to throw an unhandled exception out of process(), or to allocate an arbitrary amount of memory in one request, and an application whose language handle subclass defines side effecting public methods makes those callable with attacker chosen arguments. The dumped type constraint message is bounded to the exception, because both dumpers quote non-numeric elements so the method slot is never an attacker chosen name. The built-in messages pass fixed templates with the value in an argument slot, where it stays inert, and the built-in field types attach explicit message callbacks, so neither is affected.

NAME

HTML::FormHandler::Render::RepeatableJs - role providing method to construct repeatable javascript

VERSION

version 0.40068

SYNOPSIS

Creates jQuery javascript to add and delete repeatable elements.

Note: This is still EXPERIMENTAL. This is an EXAMPLE. Changes are very likely to occur. Javascript is not guaranteed to be best practice. It will not work on all rendered repeatables (requires wrapper with id). It is strongly suggested that you make your own role if you use it. Then you can modify it as needed. Or just write out the rep_ data to javascript variables, and write the function in javascript. This function uses a plain javascript confirmation dialog. You almost certainly want to do something else. This javascript depends on the Repeatable field having a 'controls' div class in order to position the new elements. Use the Bootstrap wrapper or the 'controls_div' tag on the Simple wrapper.

A role to be used in a Form Class:

package MyApp::Form::Test;
use HTML::FormHandler::Moose;
extends 'HTML::FormHandler';
with 'HTML::FormHandler::Render::RepeatableJs';
...

DESCRIPTION

This contains one method, 'render_repeatable_js'. It's designed to be used in a template, something like:

[% WRAPPER "wrapper.tt" %]
[% form.render_repeatable_js %]
<h1>Editing Object .... </h1>
[% form.render %]
[% END -%]

It will render javascript which can be used with the AddElement field, and setting the 'setup_for_js' flag in the Repeatable field to add the ability to dynamically add a new repeatable element in a form.

Note: this code is provided as an example. You may need to write your own javascript function if your situation is different.

Some of the extra information (level) in this function is in preparation for handling nested repeatables, but it's not supported yet.

This function operates on HTML elements that have the id of the repeatable element. That requires that the wrapper have the repeatable instance ID (now rendered by default). If you don't have wrappers around your repeatable elements, this won't work.

See HTML::FormHandler::Field::AddElement for an example of rendering an HTML element that can be used to provide the AddElement button. See that field for the requirements for the add HTML.

See HTML::FormHandler::Field::RmElement for an example of rendering an HTML element that can be used to provide a 'remove' button. See that field for the requirements for the remove HTML.

NAME

HTML::FormHandler::Render::RepeatableJs

AUTHOR

FormHandler Contributors - see HTML::FormHandler

COPYRIGHT AND LICENSE

This software is copyright (c) 2017 by Gerda Shank.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.