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

Provided by: perl-doc_5.38.2-3.2ubuntu0.1_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.