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perl-5.42.2
⭐ Starred 2013 / User::grent
Security Advisories (3)
CVE-2026-13221 (2026-07-13)

Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk. When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error. A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.

CVE-2026-57432 (2026-07-13)

Perl versions through 5.43.10 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves with a signed length comparison that passes when the length is negative, advancing the buffer pointer out of bounds. A template derived from untrusted input can read heap memory past the buffer and return it to the caller.

CVE-2026-8376 (2026-05-25)

Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer. A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.

NAME

User::grent - by-name interface to Perl's built-in getgr*() functions

SYNOPSIS

use User::grent;
my $gr = getgrgid(0) or die "No group zero";
if ( $gr->name eq 'wheel' && @{$gr->members} > 1 ) {
    print "gid zero name wheel, with other members";
} 

use User::grent qw(:FIELDS);
getgrgid(0) or die "No group zero";
if ( $gr_name eq 'wheel' && @gr_members > 1 ) {
    print "gid zero name wheel, with other members";
} 

my $gr = getgr($whoever);

DESCRIPTION

This module's default exports override the core getgrent(), getgrgid(), and getgrnam() functions, replacing them with versions that return "User::grent" objects. This object has methods that return the similarly named structure field name from the C's passwd structure from grp.h; namely name, passwd, gid, and members (not mem). The first three return scalars, the last an array reference.

You may also import all the structure fields directly into your namespace as regular variables using the :FIELDS import tag. (Note that this still overrides your core functions.) Access these fields as variables named with a preceding gr_. Thus, $group_obj->gid() corresponds to $gr_gid if you import the fields. Array references are available as regular array variables, so @{ $group_obj->members() } would be simply @gr_members.

The getgr() function is a simple front-end that forwards a numeric argument to getgrgid() and the rest to getgrnam().

To access this functionality without the core overrides, pass the use an empty import list, and then access function functions with their full qualified names. On the other hand, the built-ins are still available via the CORE:: pseudo-package.

NOTE

While this class is currently implemented using the Class::Struct module to build a struct-like class, you shouldn't rely upon this.

AUTHOR

Tom Christiansen