/ 
HTML-FormFu-2.07
/ HTML::FormFu::Filter
Security Advisories (1)
CVE-2026-19873 (2026-08-31)

HTML::FormFu versions through 2.08 for Perl allow resource exhaustion via an unbounded repeat count from the query string in Repeatable elements. When a Repeatable element has counter_name set, its process method reads the repeat count from the named query string parameter, checks only that it is a positive integer, and passes it to repeat, which deep-clones the element's child subtree once per iteration. Nothing caps the value, and no attribute lets an application impose a limit. The count is read on every request, before the form decides whether it was submitted, so a plain GET reaches the clone loop with no credentials, no session and no request body. Nesting multiplies: a Repeatable inside a Repeatable takes a counter at each level, so an outer and an inner value of 100 build 10,000 clones. Once the form is submitted, each cloned field's constraints scan the whole element tree in _find_field_value, so cost grows faster than linearly with the count. A single request exhausts memory and CPU. The latest release on CPAN is 2.07, from 2018. Version 2.08 exists only in the git repository.

NAME

HTML::FormFu::Filter - Filter Base Class

VERSION

version 2.07

SYNOPSIS

---
elements:
  - type: Text
    name: foo
    filters:
      - type: Encode
        candidates:
          - utf8
          - Hebrew
  - type: Text
    name: bar
    filters:
      - LowerCase
      - Encode
filters:
  - TrimEdges

DESCRIPTION

filters() and filter can be called on any form, block element (includes fieldsets) or field element.

If called on a field element, no name argument should be passed.

If called on a form or block element, if no name argument is provided, a new filter is created for and added to every field on that form or block.

See "FORM LOGIC AND VALIDATION" in HTML::FormFu for further details.

METHODS

type

Returns the type argument originally used to create the filter.

localise_args

Provide arguments that should be passed to localize to replace [_1], [_2], etc. in the localized string.

parent

Returns the HTML::FormFu::Role::Element::Field object that the filter is associated with.

get_parent

Arguments: \%options

Traverses the parent hierarchy, returning the first parent that matches the supplied options.

form

Returns the HTML::FormFu object that the filter's field is attached to.

name

Shorthand for $filter->parent->name

CORE FILTERS

HTML::FormFu::Filter::Callback
HTML::FormFu::Filter::CompoundJoin
HTML::FormFu::Filter::CompoundSprintf
HTML::FormFu::Filter::CopyValue
HTML::FormFu::Filter::Default
HTML::FormFu::Filter::Encode
HTML::FormFu::Filter::ForceListValue
HTML::FormFu::Filter::FormatNumber
HTML::FormFu::Filter::HTMLEscape
HTML::FormFu::Filter::HTMLScrubber
HTML::FormFu::Filter::LowerCase
HTML::FormFu::Filter::NonNumeric
HTML::FormFu::Filter::Regex
HTML::FormFu::Filter::Split
HTML::FormFu::Filter::TrimEdges
HTML::FormFu::Filter::UpperCase
HTML::FormFu::Filter::Whitespace

FILTER BASE CLASSES

The following are base classes for other filters, and generally needn't be used directly.

HTML::FormFu::Filter::_Compound

AUTHOR

Carl Franks, cfranks@cpan.org

Based on the original source code of HTML::Widget::Filter, by Sebastian Riedel.

LICENSE

This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

Carl Franks <cpan@fireartist.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Carl Franks.

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