Ubuntu Manpage: perl5283delta - what is new for perl v5.28.3

Provided by: perl-doc_5.34.0-5ubuntu1_all

NAME

       perl5283delta - what is new for perl v5.28.3

DESCRIPTION

       This document describes differences between the 5.28.2 release and the 5.28.3 release.

       If you are upgrading from an earlier release such as 5.28.1, first read perl5282delta,
       which describes differences between 5.28.1 and 5.28.2.

Security

[CVE-2020-10543] Buffer overflow caused by a crafted regular expression
A signed "size_t" integer overflow in the storage space calculations for nested regular
expression quantifiers could cause a heap buffer overflow in Perl's regular expression
compiler that overwrites memory allocated after the regular expression storage space with
attacker supplied data.

The target system needs a sufficient amount of memory to allocate partial expansions of
the nested quantifiers prior to the overflow occurring. This requirement is unlikely to
be met on 64-bit systems.

Discovered by: ManhND of The Tarantula Team, VinCSS (a member of Vingroup).

[CVE-2020-10878] Integer overflow via malformed bytecode produced by a crafted regular
expression
Integer overflows in the calculation of offsets between instructions for the regular
expression engine could cause corruption of the intermediate language state of a compiled
regular expression. An attacker could abuse this behaviour to insert instructions into
the compiled form of a Perl regular expression.

Discovered by: Hugo van der Sanden and Slaven Rezic.

[CVE-2020-12723] Buffer overflow caused by a crafted regular expression
Recursive calls to "S_study_chunk()" by Perl's regular expression compiler to optimize the
intermediate language representation of a regular expression could cause corruption of the
intermediate language state of a compiled regular expression.

Discovered by: Sergey Aleynikov.

Additional Note
An application written in Perl would only be vulnerable to any of the above flaws if it
evaluates regular expressions supplied by the attacker. Evaluating regular expressions in
this fashion is known to be dangerous since the regular expression engine does not protect
against denial of service attacks in this usage scenario.

Incompatible Changes

       There are no changes intentionally incompatible with Perl 5.28.2.  If any exist, they are
       bugs, and we request that you submit a report.  See "Reporting Bugs" below.

Modules and Pragmata

   Updated Modules and Pragmata
       •   Module::CoreList has been upgraded from version 5.20190419 to 5.20200601_28.

Testing

       Tests were added and changed to reflect the other additions and changes in this release.

Acknowledgements

       Perl 5.28.3 represents approximately 13 months of development since Perl 5.28.2 and
       contains approximately 3,100 lines of changes across 48 files from 16 authors.

       Excluding auto-generated files, documentation and release tools, there were approximately
       1,700 lines of changes to 9 .pm, .t, .c and .h files.

       Perl continues to flourish into its fourth decade thanks to a vibrant community of users
       and developers.  The following people are known to have contributed the improvements that
       became Perl 5.28.3:

       Chris 'BinGOs' Williams, Dan Book, Hugo van der Sanden, James E Keenan, John Lightsey,
       Karen Etheridge, Karl Williamson, Matthew Horsfall, Max Maischein, Nicolas R., Renee
       Baecker, Sawyer X, Steve Hay, Tom Hukins, Tony Cook, Zak B.  Elep.

       The list above is almost certainly incomplete as it is automatically generated from
       version control history.  In particular, it does not include the names of the (very much
       appreciated) contributors who reported issues to the Perl bug tracker.

       Many of the changes included in this version originated in the CPAN modules included in
       Perl's core.  We're grateful to the entire CPAN community for helping Perl to flourish.

       For a more complete list of all of Perl's historical contributors, please see the AUTHORS
       file in the Perl source distribution.

Reporting Bugs

       If you find what you think is a bug, you might check the perl bug database at
       <https://github.com/Perl/perl5/issues>.  There may also be information at
       <https://www.perl.org/>, the Perl Home Page.

       If you believe you have an unreported bug, please open an issue at
       <https://github.com/Perl/perl5/issues>.  Be sure to trim your bug down to a tiny but
       sufficient test case.

       If the bug you are reporting has security implications which make it inappropriate to send
       to a public issue tracker, then see "SECURITY VULNERABILITY CONTACT INFORMATION" in
       perlsec for details of how to report the issue.

Give Thanks

       If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so
       by running the "perlthanks" program:

           perlthanks

       This will send an email to the Perl 5 Porters list with your show of thanks.