/ 
perl-5.25.4
⭐ Starred 2013
/ Internals
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

Internals - Reserved special namespace for internals related functions

SYNOPSIS

$is_ro= Internals::SvREADONLY($x)
$refcnt= Internals::SvREFCNT($x)

DESCRIPTION

The Internals namespace is used by the core Perl development team to expose certain low level internals routines for testing and other purposes.

In theory these routines were not and are not intended to be used outside of the perl core, and are subject to change and removal at any time.

In practice people have come to depend on these over the years, despite being historically undocumented, so we will provide some level of forward compatibility for some time. Nevertheless you can assume that any routine documented here is experimental or deprecated and you should find alternatives to their use.

FUNCTIONS

SvREFCNT(THING [, $value])

Historically Perl has been a refcounted language. This means that each variable tracks how many things reference it, and when the variable is no longer referenced it will automatically free itself. In theory Perl code should not have to care about this, and in a future version Perl might change to some other strategy, although in practice this is unlikely.

This function allows one to violate the abstraction of variables and get or set the refcount of a variable, and in generally is really only useful in code that is testing refcount behavior.

*NOTE* You are strongly discouraged from using this function in non-test code and especially discouraged from using the set form of this function. The results of doing so may result in segmentation faults or other undefined behavior.

SvREADONLY(THING, [, $value])

Set or get whether a variable is readonly or not. Exactly what the readonly flag means depend on the type of the variable affected and the version of perl used.

You are strongly discouraged from using this function directly. It is used by various core modules, like Hash::Util, and the constant pragma to implement higher-level behavior which should be used instead.

See the core implementation for the exact meaning of the readonly flag for each internal variable type.

AUTHOR

Perl core development team.

SEE ALSO

perlguts universal.c