/ 
perl-5.34.0-RC2
⭐ Starred 2013 / Config::Perl::V
Security Advisories (6)
CVE-2022-48522 (2023-08-22)

In Perl 5.34.0, function S_find_uninit_var in sv.c has a stack-based crash that can lead to remote code execution or local privilege escalation.

CVE-2023-47038 (2023-10-30)

A crafted regular expression when compiled by perl 5.30.0 through 5.38.0 can cause a one attacker controlled byte buffer overflow in a heap allocated buffer

CVE-2024-56406 (2025-04-13)

A heap buffer overflow vulnerability was discovered in Perl. Release branches 5.34, 5.36, 5.38 and 5.40 are affected, including development versions from 5.33.1 through 5.41.10. When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`.    $ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;'    Segmentation fault (core dumped) It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.

CVE-2025-40909 (2025-05-30)

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

CVE-2023-47039 (2023-10-30)

Perl for Windows relies on the system path environment variable to find the shell (cmd.exe). When running an executable which uses Windows Perl interpreter, Perl attempts to find and execute cmd.exe within the operating system. However, due to path search order issues, Perl initially looks for cmd.exe in the current working directory. An attacker with limited privileges can exploit this behavior by placing cmd.exe in locations with weak permissions, such as C:\ProgramData. By doing so, when an administrator attempts to use this executable from these compromised locations, arbitrary code can be executed.

CVE-2023-47100

In Perl before 5.38.2, S_parse_uniprop_string in regcomp.c can write to unallocated space because a property name associated with a \p{...} regular expression construct is mishandled. The earliest affected version is 5.30.0.

NAME

Config::Perl::V - Structured data retrieval of perl -V output

SYNOPSIS

use Config::Perl::V;

my $local_config = Config::Perl::V::myconfig ();
print $local_config->{config}{osname};

DESCRIPTION

$conf = myconfig ()

This function will collect the data described in "The hash structure" below, and return that as a hash reference. It optionally accepts an option to include more entries from %ENV. See "environment" below.

Note that this will not work on uninstalled perls when called with -I/path/to/uninstalled/perl/lib, but it works when that path is in $PERL5LIB or in $PERL5OPT, as paths passed using -I are not known when the -V information is collected.

$conf = plv2hash ($text [, ...])

Convert a sole 'perl -V' text block, or list of lines, to a complete myconfig hash. All unknown entries are defaulted.

$info = summary ([$conf])

Return an arbitrary selection of the information. If no $conf is given, myconfig () is used instead.

$md5 = signature ([$conf])

Return the MD5 of the info returned by summary () without the config_args entry.

If Digest::MD5 is not available, it return a string with only 0's.

The hash structure

The returned hash consists of 4 parts:

build

This information is extracted from the second block that is emitted by perl -V, and usually looks something like

 Characteristics of this binary (from libperl):
   Compile-time options: DEBUGGING USE_64_BIT_INT USE_LARGE_FILES
   Locally applied patches:
	 defined-or
	 MAINT24637
   Built under linux
   Compiled at Jun 13 2005 10:44:20
   @INC:
     /usr/lib/perl5/5.8.7/i686-linux-64int
     /usr/lib/perl5/5.8.7
     /usr/lib/perl5/site_perl/5.8.7/i686-linux-64int
     /usr/lib/perl5/site_perl/5.8.7
     /usr/lib/perl5/site_perl
     .

or

 Characteristics of this binary (from libperl):
   Compile-time options: DEBUGGING MULTIPLICITY
			 PERL_DONT_CREATE_GVSV PERL_IMPLICIT_CONTEXT
			 PERL_MALLOC_WRAP PERL_TRACK_MEMPOOL
			 PERL_USE_SAFE_PUTENV USE_ITHREADS
			 USE_LARGE_FILES USE_PERLIO
			 USE_REENTRANT_API
   Built under linux
   Compiled at Jan 28 2009 15:26:59

This information is not available anywhere else, including %Config, but it is the information that is only known to the perl binary.

The extracted information is stored in 5 entries in the build hash:

osname

This is most likely the same as $Config{osname}, and was the name known when perl was built. It might be different if perl was cross-compiled.

The default for this field, if it cannot be extracted, is to copy $Config{osname}. The two may be differing in casing (OpenBSD vs openbsd).

stamp

This is the time string for which the perl binary was compiled. The default value is 0.

options

This is a hash with all the known defines as keys. The value is either 0, which means unknown or unset, or 1, which means defined.

derived

As some variables are reported by a different name in the output of perl -V than their actual name in %Config, I decided to leave the config entry as close to reality as possible, and put in the entries that might have been guessed by the printed output in a separate block.

patches

This is a list of optionally locally applied patches. Default is an empty list.

environment

By default this hash is only filled with the environment variables out of %ENV that start with PERL, but you can pass the env option to myconfig to get more

my $conf = Config::Perl::V::myconfig ({ env => qr/^ORACLE/ });
my $conf = Config::Perl::V::myconfig ([ env => qr/^ORACLE/ ]);
config

This hash is filled with the variables that perl -V fills its report with, and it has the same variables that Config::myconfig returns from %Config.

inc

This is the list of default @INC.

REASONING

This module was written to be able to return the configuration for the currently used perl as deeply as needed for the CPANTESTERS framework. Up until now they used the output of myconfig as a single text blob, and so it was missing the vital binary characteristics of the running perl and the optional applied patches.

BUGS

Please feedback what is wrong

TODO

* Implement retrieval functions/methods
* Documentation
* Error checking
* Tests

AUTHOR

H.Merijn Brand <h.m.brand@xs4all.nl>

COPYRIGHT AND LICENSE

Copyright (C) 2009-2020 H.Merijn Brand

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