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Dancer2-2.1.0
⭐ Starred 552 / Dancer2::Core::Role::SessionFactory::File
Security Advisories (1)
CVE-2026-13577 (2026-07-20)

Dancer2 versions through 2.1.0 for Perl generate insecure session ids when CSPRNG modules are unavailable. Dancer2::Core::Role::SessionFactory::generate_id silently falls back to a built-in rand-derived session id when both Math::Random::ISAAC::XS and Crypt::URandom are unavailable. The fallback session id is generated from a SHA-1 hash of a call to the built-in rand function, the absolute path of the Dancer2::Core::Role::SessionFactory module, an internal counter, the process id, the module instance memory address, and a shuffled string of characters (using the List::Util::shuffle function, which also uses the built-in rand function). These are all low-entropy and easily guessed sources. The built-in rand() function is seeded with 32-bits and considered unsuitable for security applications. Predictable session ids could allow an attacker to gain access to systems.

NAME

Dancer2::Core::Role::SessionFactory::File - Role for file-based session factories

VERSION

version 2.1.0

DESCRIPTION

This is a specialized SessionFactory role for storing session data in files.

This role manages the files. Classes consuming it only need to handle serialization and deserialization.

Classes consuming this must satisfy three requirements: _suffix, _freeze_to_handle and _thaw_from_handle.

package Dancer2::Session::XYX;

use Dancer2::Core::Types;
use Moo;

has _suffix => (
    is      => 'ro',
    isa     => Str,
    default => sub { '.xyz' },
);

with 'Dancer2::Core::Role::SessionFactory::File';

sub _freeze_to_handle {
    my ($self, $fh, $data) = @_;

    # ... do whatever to get data into $fh

    return;
}

sub _thaw_from_handle {
    my ($self, $fh) = @_;
    my $data;

    # ... do whatever to get data from $fh

    return $data;
}

1;

ATTRIBUTES

session_dir

Where to store the session files. Defaults to "./sessions".

AUTHOR

Dancer Core Developers

COPYRIGHT AND LICENSE

This software is copyright (c) 2026 by Alexis Sukrieh.

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