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Dancer-1.1902 UNAUTHORIZED RELEASE
⭐ Starred 738 / Dancer::Plugin
Security Advisories (3)
CVE-2026-5080 (2026-04-30)

Dancer::Session::Abstract versions through 1.3522 for Perl generates session ids insecurely. The session id is generated from summing the character codepoints of the absolute pathname with the process id, the epoch time and calls to the built-in rand() function to return a number between 0 and 999-billion, and concatenating that result three times. The path name might be known or guessed by an attacker, especially for applications known to be written using Dancer with standard installation locations. The epoch time can be guessed by an attacker, and may be leaked in the HTTP header. The process id comes from a small set of numbers, and workers may have sequential process ids. The built-in rand() function is seeded with 32-bits and is considered unsuitable for security applications. Predictable session ids could allow an attacker to gain access to systems.

CVE-2012-5572 (2014-05-30)

CRLF injection vulnerability in the cookie method allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a cookie name.

CVE-2011-1589 (2011-04-05)

Directory traversal vulnerability (Mojolicious report, but Dancer was vulnerable as well).

NAME

Dancer::Plugin - helper for writing Dancer plugins

DESCRIPTION

Create plugins for Dancer

SYNOPSIS

package Dancer::Plugin::LinkBlocker;
use Dancer ':syntax';
use Dancer::Plugin;

register block_links_from => sub {
  my $conf = plugin_setting();
  my $re = join ('|', @{$conf->{hosts}});
  before sub {
      if (request->referer && request->referer =~ /$re/) {
          status 403 || $conf->{http_code};
      }
  };
};

register_plugin;
1;

And in your application:

package My::Webapp;

use Dancer ':syntax';
use Dancer::Plugin::LinkBlocker;

block_links_from; # this is exported by the plugin

PLUGINS

You can extend Dancer by writing your own Plugin.

A plugin is a module that exports a bunch of symbols to the current namespace (the caller will see all the symbols defined via register).

Note that you have to use the plugin wherever you want to use its symbols. For instance, if you have Webapp::App1 and Webapp::App2, both loaded from your main application, they both need to use FooPlugin if they want to use the symbols exported by FooPlugin.

METHODS

register

Lets you define a keyword that will be exported by the plugin.

register my_symbol_to_export => sub {
    # ... some code 
};
register_plugin

A Dancer plugin must end with this statement. This lets the plugin register all the symbols define with register as exported symbols (via the Exporter module).

A Dancer plugin inherits from Dancer::Plugin and Exporter transparently.

plugin_setting

Configuration for plugin should be structured like this in the config.yaml of the application:

plugins:
  plugin_name:
    key: value

If plugin_setting is called inside a plugin, the appropriate configuration will be returned. The plugin_name should be the name of the package, or, if the plugin name is under the Dancer::Plugin:: namespace, the end part of the plugin name.

AUTHORS

This module has been written by Alexis Sukrieh and others.

LICENSE

This module is free software and is published under the same terms as Perl itself.