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perl-5.14.3
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/ User::pwent
Security Advisories (18)
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-2018-6913 (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-2018-18313 (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-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-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-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-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-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-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.

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-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.

NAME

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

SYNOPSIS

use User::pwent;
$pw = getpwnam('daemon')       || die "No daemon user";
if ( $pw->uid == 1 && $pw->dir =~ m#^/(bin|tmp)?\z#s ) {
    print "gid 1 on root dir";
}

$real_shell = $pw->shell || '/bin/sh';

for (($fullname, $office, $workphone, $homephone) =
       split /\s*,\s*/, $pw->gecos)
{
   s/&/ucfirst(lc($pw->name))/ge;
}

use User::pwent qw(:FIELDS);
getpwnam('daemon')             || die "No daemon user";
if ( $pw_uid == 1 && $pw_dir =~ m#^/(bin|tmp)?\z#s ) {
    print "gid 1 on root dir";
}

$pw = getpw($whoever);

use User::pwent qw/:DEFAULT pw_has/;
if (pw_has(qw[gecos expire quota])) { .... }
if (pw_has("name uid gid passwd"))  { .... }
print "Your struct pwd has: ", scalar pw_has(), "\n";

DESCRIPTION

This module's default exports override the core getpwent(), getpwuid(), and getpwnam() functions, replacing them with versions that return User::pwent objects. This object has methods that return the similarly named structure field name from the C's passwd structure from pwd.h, stripped of their leading "pw_" parts, namely name, passwd, uid, gid, change, age, quota, comment, class, gecos, dir, shell, and expire. The passwd, gecos, and shell fields are tainted when running in taint mode.

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 pw_ in front their method names. Thus, $passwd_obj->shell corresponds to $pw_shell if you import the fields.

The getpw() function is a simple front-end that forwards a numeric argument to getpwuid() and the rest to getpwnam().

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. The built-ins are always still available via the CORE:: pseudo-package.

System Specifics

Perl believes that no machine ever has more than one of change, age, or quota implemented, nor more than one of either comment or class. Some machines do not support expire, gecos, or allegedly, passwd. You may call these methods no matter what machine you're on, but they return undef if unimplemented.

You may ask whether one of these was implemented on the system Perl was built on by asking the importable pw_has function about them. This function returns true if all parameters are supported fields on the build platform, false if one or more were not, and raises an exception if you asked about a field that Perl never knows how to provide. Parameters may be in a space-separated string, or as separate arguments. If you pass no parameters, the function returns the list of struct pwd fields supported by your build platform's C library, as a list in list context, or a space-separated string in scalar context. Note that just because your C library had a field doesn't necessarily mean that it's fully implemented on that system.

Interpretation of the gecos field varies between systems, but traditionally holds 4 comma-separated fields containing the user's full name, office location, work phone number, and home phone number. An & in the gecos field should be replaced by the user's properly capitalized login name. The shell field, if blank, must be assumed to be /bin/sh. Perl does not do this for you. The passwd is one-way hashed garble, not clear text, and may not be unhashed save by brute-force guessing. Secure systems use more a more secure hashing than DES. On systems supporting shadow password systems, Perl automatically returns the shadow password entry when called by a suitably empowered user, even if your underlying vendor-provided C library was too short-sighted to realize it should do this.

See passwd(5) and getpwent(3) for details.

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

HISTORY

March 18th, 2000

Reworked internals to support better interface to dodgey fields than normal Perl function provides. Added pw_has() field. Improved documentation.