It was found that the pack() function in the 32-bit version of the perl interpreter was vulnerable to heap buffer overflow via the packing template. An attacker, able to provide a specially crafted template, could use this flaw to crash the interpreter.
A flaw was found in Perl 5. Vulnerable code in pp_pack.c file accepts either large blocks of data from untrusted sources and/or duplicates such blocks, which allows an attacker to exploit this vulnerability at runtime by supplying malicious crafted data. This could result in a denial-of-service (DoS) attack.
Reproducer for 32-bit architecture:
$ perl -e 'pack "c10f1073741823"'
Segmentation fault (core dumped)
Perl 5 Porters published the fix for Perl 5.26.1 at <https://perl5.git.perl.org/perl.git/commit/0fcf83230df5f8c52602ae22fde57c7ea885534d> and in Perl-5.26.2-RC1 and 5.24.4-RC1 tar balls.
Created perl tracking bugs for this issue:
Affects: fedora-all [bug 1567776]
- (perl #131844) fix various space calculation issues in pp_pack.c
The 64-bit versions of perl have not been found to be affected. As a result, this issue did not affect the versions of perl as shipped with Red Hat Enterprise Linux 7, and the versions of rh-perl526-perl, rh-perl524-perl and rh-perl520-perl as shipped with Red Hat Software Collections.
This issue affects the 32bit versions of perl as shipped with Red Hat Enterprise Linux 6. Red Hat Enterprise Linux 6 is now in Maintenance Support 2 Phase of the support and maintenance life cycle. This has been rated as having a security impact of Low, and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
This issue may affect the versions of perl as shipped with Red Hat Enterprise Linux 5. Red Hat Enterprise Linux 5 is now in Extended Life Cycle phase of the support and maintenance life cycle. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
Name: Perl 5 Porters
Upstream: GwanYeong Kim