/ 
perl-5.25.4
⭐ Starred 2013
/ arybase
Security Advisories (11)
CVE-2020-12723 (2020-06-05)

regcomp.c in Perl before 5.30.3 allows a buffer overflow via a crafted regular expression because of recursive S_study_chunk calls.

CVE-2020-10878 (2020-06-05)

Perl before 5.30.3 has an integer overflow related to mishandling of a "PL_regkind[OP(n)] == NOTHING" situation. A crafted regular expression could lead to malformed bytecode with a possibility of instruction injection.

CVE-2020-10543 (2020-06-05)

Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression quantifiers have an integer overflow.

CVE-2018-18314 (2018-12-07)

Perl before 5.26.3 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

CVE-2018-18313 (2018-12-07)

Perl before 5.26.3 has a buffer over-read via a crafted regular expression that triggers disclosure of sensitive information from process memory.

CVE-2018-18312 (2018-12-05)

Perl before 5.26.3 and 5.28.0 before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

CVE-2018-18311 (2018-12-07)

Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

CVE-2023-47100

In Perl before 5.38.2, S_parse_uniprop_string in regcomp.c can write to unallocated space because a property name associated with a \p{...} regular expression construct is mishandled. The earliest affected version is 5.30.0.

CVE-2024-56406 (2025-04-13)

A heap buffer overflow vulnerability was discovered in Perl. When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`.    $ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;'    Segmentation fault (core dumped) It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.

CVE-2025-40909 (2025-05-30)

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

CVE-2023-47039 (2023-10-30)

Perl for Windows relies on the system path environment variable to find the shell (cmd.exe). When running an executable which uses Windows Perl interpreter, Perl attempts to find and execute cmd.exe within the operating system. However, due to path search order issues, Perl initially looks for cmd.exe in the current working directory. An attacker with limited privileges can exploit this behavior by placing cmd.exe in locations with weak permissions, such as C:\ProgramData. By doing so, when an administrator attempts to use this executable from these compromised locations, arbitrary code can be executed.

NAME

arybase - Set indexing base via $[

SYNOPSIS

$[ = 1;

@a = qw(Sun Mon Tue Wed Thu Fri Sat);
print $a[3], "\n";  # prints Tue

DESCRIPTION

This module implements Perl's $[ variable. You should not use it directly.

Assigning to $[ has the compile-time effect of making the assigned value, converted to an integer, the index of the first element in an array and the first character in a substring, within the enclosing lexical scope.

It can be written with or without local:

$[ = 1;
local $[ = 1;

It only works if the assignment can be detected at compile time and the value assigned is constant.

It affects the following operations:

$array[$element]
@array[@slice]
$#array
(list())[$slice]
splice @array, $index, ...
each @array
keys @array

index $string, $substring  # return value is affected
pos $string
substr $string, $offset, ...

As with the default base of 0, negative bases count from the end of the array or string, starting with -1. If $[ is a positive integer, indices from $[-1 to 0 also count from the end. If $[ is negative (why would you do that, though?), indices from $[ to 0 count from the beginning of the string, but indices below $[ count from the end of the string as though the base were 0.

Prior to Perl 5.16, indices from 0 to $[-1 inclusive, for positive values of $[, behaved differently for different operations; negative indices equal to or greater than a negative $[ likewise behaved inconsistently.

HISTORY

Before Perl 5, $[ was a global variable that affected all array indices and string offsets.

Starting with Perl 5, it became a file-scoped compile-time directive, which could be made lexically-scoped with local. "File-scoped" means that the $[ assignment could leak out of the block in which occurred:

{
    $[ = 1;
    # ... array base is 1 here ...
}
# ... still 1, but not in other files ...

In Perl 5.10, it became strictly lexical. The file-scoped behaviour was removed (perhaps inadvertently, but what's done is done).

In Perl 5.16, the implementation was moved into this module, and out of the Perl core. The erratic behaviour that occurred with indices between -1 and $[ was made consistent between operations, and, for negative bases, indices from $[ to -1 inclusive were made consistent between operations.

BUGS

Error messages that mention array indices use the 0-based index.

keys $arrayref and each $arrayref do not respect the current value of $[.

SEE ALSO

"$[" in perlvar, Array::Base and String::Base.