/ 
perl-5.9.3
/ PerlIO::via
Security Advisories (27)
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-2010-1158 (2010-04-20)

Integer overflow in the regular expression engine in Perl 5.8.x allows context-dependent attackers to cause a denial of service (stack consumption and application crash) by matching a crafted regular expression against a long string.

CVE-2009-3626 (2009-10-29)

Perl 5.10.1 allows context-dependent attackers to cause a denial of service (application crash) via a UTF-8 character with a large, invalid codepoint, which is not properly handled during a regular-expression match.

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-2013-7422 (2015-08-16)

Integer underflow in regcomp.c in Perl before 5.20, as used in Apple OS X before 10.10.5 and other products, allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via a long digit string associated with an invalid backreference within a regular expression.

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-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.

CVE-2016-1238 (2016-08-02)

(1) cpan/Archive-Tar/bin/ptar, (2) cpan/Archive-Tar/bin/ptardiff, (3) cpan/Archive-Tar/bin/ptargrep, (4) cpan/CPAN/scripts/cpan, (5) cpan/Digest-SHA/shasum, (6) cpan/Encode/bin/enc2xs, (7) cpan/Encode/bin/encguess, (8) cpan/Encode/bin/piconv, (9) cpan/Encode/bin/ucmlint, (10) cpan/Encode/bin/unidump, (11) cpan/ExtUtils-MakeMaker/bin/instmodsh, (12) cpan/IO-Compress/bin/zipdetails, (13) cpan/JSON-PP/bin/json_pp, (14) cpan/Test-Harness/bin/prove, (15) dist/ExtUtils-ParseXS/lib/ExtUtils/xsubpp, (16) dist/Module-CoreList/corelist, (17) ext/Pod-Html/bin/pod2html, (18) utils/c2ph.PL, (19) utils/h2ph.PL, (20) utils/h2xs.PL, (21) utils/libnetcfg.PL, (22) utils/perlbug.PL, (23) utils/perldoc.PL, (24) utils/perlivp.PL, and (25) utils/splain.PL in Perl 5.x before 5.22.3-RC2 and 5.24 before 5.24.1-RC2 do not properly remove . (period) characters from the end of the includes directory array, which might allow local users to gain privileges via a Trojan horse module under the current working directory.

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-2012-5195 (2012-12-18)

Heap-based buffer overflow in the Perl_repeatcpy function in util.c in Perl 5.12.x before 5.12.5, 5.14.x before 5.14.3, and 5.15.x before 15.15.5 allows context-dependent attackers to cause a denial of service (memory consumption and crash) or possibly execute arbitrary code via the 'x' string repeat operator.

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-2026-15534 (2026-08-09)

Perl versions through 5.45.1 have out-of-bounds heap reads and writes during regular expression matching via an undersized superlinear cache in S_regmatch. The regex engine's superlinear cache holds one bit per subject position for each participating WHILEM node, so the bit count is the subject length plus one times the number of nodes. Nothing checks that product for positive overflow of the signed 32-bit count: a 286331153 byte subject matched against a pattern with 15 participating nodes stores the count as 14, leaving a two byte cache. The cache is then indexed from the real match position and node number, so reads go past the end of the allocation, and on failure CACHEsayNO sets a bit past it. A caller that matches an attacker controlled subject of this size against a pattern of this shape can crash the process or corrupt heap memory.

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-2015-8608 (2017-02-07)

The VDir::MapPathA and VDir::MapPathW functions in Perl 5.22 allow remote attackers to cause a denial of service (out-of-bounds read) and possibly execute arbitrary code via a crafted (1) drive letter or (2) pInName argument.

CVE-2011-2728 (2012-12-21)

The bsd_glob function in the File::Glob module for Perl before 5.14.2 allows context-dependent attackers to cause a denial of service (crash) via a glob expression with the GLOB_ALTDIRFUNC flag, which triggers an uninitialized pointer dereference.

CVE-2018-6913 (2018-04-17)

Heap-based buffer overflow in the pack function in Perl before 5.26.2 allows context-dependent attackers to execute arbitrary code via a large item count.

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-2018-18312 (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-2015-8853 (2016-05-25)

The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to cause a denial of service (infinite loop) via crafted utf-8 data, as demonstrated by "a\x80."

CVE-2013-1667 (2013-03-14)

The rehash mechanism in Perl 5.8.2 through 5.16.x allows context-dependent attackers to cause a denial of service (memory consumption and crash) via a crafted hash key.

CVE-2010-4777 (2014-02-10)

The Perl_reg_numbered_buff_fetch function in Perl 5.10.0, 5.12.0, 5.14.0, and other versions, when running with debugging enabled, allows context-dependent attackers to cause a denial of service (assertion failure and application exit) via crafted input that is not properly handled when using certain regular expressions, as demonstrated by causing SpamAssassin and OCSInventory to crash.

CVE-2005-3962 (2005-12-01)

Integer overflow in the format string functionality (Perl_sv_vcatpvfn) in Perl 5.9.2 and 5.8.6 Perl allows attackers to overwrite arbitrary memory and possibly execute arbitrary code via format string specifiers with large values, which causes an integer wrap and leads to a buffer overflow, as demonstrated using format string vulnerabilities in Perl applications.

CVE-2016-2381 (2016-04-08)

Perl might allow context-dependent attackers to bypass the taint protection mechanism in a child process via duplicate environment variables in envp.

CVE-2011-1487 (2011-04-11)

The (1) lc, (2) lcfirst, (3) uc, and (4) ucfirst functions in Perl 5.10.x, 5.11.x, and 5.12.x through 5.12.3, and 5.13.x through 5.13.11, do not apply the taint attribute to the return value upon processing tainted input, which might allow context-dependent attackers to bypass the taint protection mechanism via a crafted string.

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

PerlIO::via - Helper class for PerlIO layers implemented in perl

SYNOPSIS

use PerlIO::via::Layer;
open($fh,"<:via(Layer)",...);

use Some::Other::Package;
open($fh,">:via(Some::Other::Package)",...);

DESCRIPTION

The PerlIO::via module allows you to develop PerlIO layers in Perl, without having to go into the nitty gritty of programming C with XS as the interface to Perl.

One example module, PerlIO::via::QuotedPrint, is included with Perl 5.8.0, and more example modules are available from CPAN, such as PerlIO::via::StripHTML and PerlIO::via::Base64. The PerlIO::via::StripHTML module for instance, allows you to say:

	use PerlIO::via::StripHTML;
	open( my $fh, "<:via(StripHTML)", "index.html" );
        my @line = <$fh>;

to obtain the text of an HTML-file in an array with all the HTML-tags automagically removed.

Please note that if the layer is created in the PerlIO::via:: namespace, it does not have to be fully qualified. The PerlIO::via module will prefix the PerlIO::via:: namespace if the specified modulename does not exist as a fully qualified module name.

EXPECTED METHODS

To create a Perl module that implements a PerlIO layer in Perl (as opposed to in C using XS as the interface to Perl), you need to supply some of the following subroutines. It is recommended to create these Perl modules in the PerlIO::via:: namespace, so that they can easily be located on CPAN and use the default namespace feature of the PerlIO::via module itself.

Please note that this is an area of recent development in Perl and that the interface described here is therefore still subject to change (and hopefully will have better documentation and more examples).

In the method descriptions below $fh will be a reference to a glob which can be treated as a perl file handle. It refers to the layer below. $fh is not passed if the layer is at the bottom of the stack, for this reason and to maintain some level of "compatibility" with TIEHANDLE classes it is passed last.

$class->PUSHED([$mode[,$fh]])

Should return an object or the class, or -1 on failure. (Compare TIEHANDLE.) The arguments are an optional mode string ("r", "w", "w+", ...) and a filehandle for the PerlIO layer below. Mandatory.

When layer is pushed as part of an open call, PUSHED will be called before the actual open occurs whether than be via OPEN, SYSOPEN, FDOPEN or by letting lower layer do the open.

$obj->POPPED([$fh])

Optional - layer is about to be removed.

$obj->UTF8($bellowFlag,[$fh])

Optional - if present it will be called immediately after PUSHED has returned. It should return true value if the layer expects data to be UTF-8 encoded. If it returns true result is as if caller had done

":via(YourClass):utf8"

If not present of it it returns false, then stream is left with flag clear. The $bellowFlag argument will be true if there is a layer below and that layer was expecting UTF-8.

$obj->OPEN($path,$mode[,$fh])

Optional - if not present lower layer does open. If present called for normal opens after layer is pushed. This function is subject to change as there is no easy way to get lower layer to do open and then regain control.

$obj->BINMODE([,$fh])

Optional - if not available layer is popped on binmode($fh) or when :raw is pushed. If present it should return 0 on success -1 on error and undef to pop the layer.

$obj->FDOPEN($fd[,$fh])

Optional - if not present lower layer does open. If present called for opens which pass a numeric file descriptor after layer is pushed. This function is subject to change as there is no easy way to get lower layer to do open and then regain control.

$obj->SYSOPEN($path,$imode,$perm,[,$fh])

Optional - if not present lower layer does open. If present called for sysopen style opens which pass a numeric mode and permissions after layer is pushed. This function is subject to change as there is no easy way to get lower layer to do open and then regain control.

$obj->FILENO($fh)

Returns a numeric value for Unix-like file descriptor. Return -1 if there isn't one. Optional. Default is fileno($fh).

$obj->READ($buffer,$len,$fh)

Returns the number of octets placed in $buffer (must be less than or equal to $len). Optional. Default is to use FILL instead.

$obj->WRITE($buffer,$fh)

Returns the number of octets from buffer that have been successfully written.

$obj->FILL($fh)

Should return a string to be placed in the buffer. Optional. If not provided must provide READ or reject handles open for reading in PUSHED.

$obj->CLOSE($fh)

Should return 0 on success, -1 on error. Optional.

$obj->SEEK($posn,$whence,$fh)

Should return 0 on success, -1 on error. Optional. Default is to fail, but that is likely to be changed in future.

$obj->TELL($fh)

Returns file postion. Optional. Default to be determined.

$obj->UNREAD($buffer,$fh)

Returns the number of octets from buffer that have been successfully saved to be returned on future FILL/READ calls. Optional. Default is to push data into a temporary layer above this one.

$obj->FLUSH($fh)

Flush any buffered write data. May possibly be called on readable handles too. Should return 0 on success, -1 on error.

$obj->SETLINEBUF($fh)

Optional. No return.

$obj->CLEARERR($fh)

Optional. No return.

$obj->ERROR($fh)

Optional. Returns error state. Default is no error until a mechanism to signal error (die?) is worked out.

$obj->EOF($fh)

Optional. Returns end-of-file state. Default is function of return value of FILL or READ.

EXAMPLES

Check the PerlIO::via:: namespace on CPAN for examples of PerlIO layers implemented in Perl. To give you an idea how simple the implementation of a PerlIO layer can look, as simple example is included here.

Example - a Hexadecimal Handle

Given the following module, PerlIO::via::Hex :

package PerlIO::via::Hex;

sub PUSHED
{
 my ($class,$mode,$fh) = @_;
 # When writing we buffer the data
 my $buf = '';
 return bless \$buf,$class;
}

sub FILL
{
 my ($obj,$fh) = @_;
 my $line = <$fh>;
 return (defined $line) ? pack("H*", $line) : undef;
}

sub WRITE
{
 my ($obj,$buf,$fh) = @_;
 $$obj .= unpack("H*", $buf);
 return length($buf);
}

sub FLUSH
{
 my ($obj,$fh) = @_;
 print $fh $$obj or return -1;
 $$obj = '';
 return 0;
}

1;

the following code opens up an output handle that will convert any output to hexadecimal dump of the output bytes: for example "A" will be converted to "41" (on ASCII-based machines, on EBCDIC platforms the "A" will become "c1")

use PerlIO::via::Hex;
open(my $fh, ">:via(Hex)", "foo.hex");

and the following code will read the hexdump in and convert it on the fly back into bytes:

open(my $fh, "<:via(Hex)", "foo.hex");