PERL5283DELTA(1) Perl Programmers Reference Guide PERL5283DELTA(1)
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.
SEE ALSO
The Changes file for an explanation of how to view exhaustive details on
what changed.
The INSTALL file for how to build Perl.
The README file for general stuff.
The Artistic and Copying files for copyright information.
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