Security Advisories (5)
CVE-2007-6341 (2008-02-08)

Allows remote attackers to cause a denial of service (program "croak") via a crafted DNS response.

CVE-2007-3409 (2007-06-26)

Net::DNS before 0.60, a Perl module, allows remote attackers to cause a denial of service (stack consumption) via a malformed compressed DNS packet with self-referencing pointers, which triggers an infinite loop.

CVE-2007-3377 (2007-06-25)

Header.pm in Net::DNS before 0.60, a Perl module, (1) generates predictable sequence IDs with a fixed increment and (2) can use the same starting ID for all child processes of a forking server, which allows remote attackers to spoof DNS responses, as originally reported for qpsmtp and spamassassin.

CVE-2026-64193 (2026-07-20)

Net::DNS versions through 1.55 for Perl allow remote execution injection via EDNS EXTENDED ERROR. Net::DNS::RR::OPT::EXTENDED_ERROR::_decompose parses the EXTRA-TEXT field of an EDNS EXTENDED-ERROR option (RFC 8914) by tokenising the raw bytes and passing the result to Perl's eval. There is some escaping done for $ and @, but not for backticks. This can be exploited for command execution if $pkt->edns->option('EXTENDED-ERROR') is called in array context, for example with a payload of {0:`"<command>"`} in EXTRA-TEXT.

CVE-2026-64194 (2026-07-20)

Net::DNS versions through 1.55 for Perl allow Denial of Service via deep DNS compression pointer chains. Net::DNS::DomainName::decode follows RFC 1035 compression pointers by recursing into itself with no depth limit. It is possible to construct a name which saturates the call stack (at least with larger TCP responses), leading to a potential Denial of Service. The guard `$link < $offset` prevents forward and circular chains, but still allows arbitrarily long backward chains. The per-offset cache (`$cache`) is populated at the start of each call and short-circuits only re-traverses of the same offset - the initial descent through a fresh chain still recurses at full depth. A crafted packet can chain two-byte compression pointers so that each one points two bytes earlier than the previous, producing a chain length of `offset / 2`. For the 14-bit pointer field (max offset 16383) this gives up to ~8191 recursive frames. For a TCP DNS message the limit is the 16-bit length field (~32767 frames). Perl's default C stack handles only a few thousand frames; beyond that the process receives SIGSEGV or similar, which is a denial-of-service for any application parsing untrusted DNS data. The vulnerability is triggered by `Net::DNS::Packet->new(\$wire)` i.e. any point where the library decodes a DNS message from the network.

NAME

Net::DNS::RR - DNS Resource Record class

SYNOPSIS

use Net::DNS::RR

DESCRIPTION

Net::DNS::RR is the base class for DNS Resource Record (RR) objects. See also the manual pages for each RR type.

METHODS

WARNING!!! Don't assume the RR objects you receive from a query are of a particular type -- always check an object's type before calling any of its methods. If you call an unknown method, you'll get a nasty warning message and Net::DNS::RR will return undef to the caller.

new (from string)

$a     = Net::DNS::RR->new("foo.example.com. 86400 A 10.1.2.3");
$mx    = Net::DNS::RR->new("example.com. 7200 MX 10 mailhost.example.com.");
$cname = Net::DNS::RR->new("www.example.com 300 IN CNAME www1.example.com");
$txt   = Net::DNS::RR->new('baz.example.com 3600 HS TXT "text record"');

Returns a Net::DNS::RR object of the appropriate type and initialized from the string passed by the user. The format of the string is that used in zone files, and is compatible with the string returned by Net::DNS::RR->string.

The name and RR type are required; all other information is optional. If omitted, the TTL defaults to 0 and the RR class defaults to IN. Omitting the optional fields is useful for creating the empty RDATA sections required for certain dynamic update operations. See the Net::DNS::Update manual page for additional examples.

All names must be fully qualified. The trailing dot (.) is optional.

new (from hash)

 $rr = Net::DNS::RR->new(
	 name    => "foo.example.com",
	 ttl     => 86400,
	 class   => "IN",
	 type    => "A",
	 address => "10.1.2.3",
 );
 
 $rr = Net::DNS::RR->new(
	 name => "foo.example.com",
	 type => "A",
 );

Returns an RR object of the appropriate type, or a Net::DNS::RR object if the type isn't implemented. See the manual pages for each RR type to see what fields the type requires.

The Name and Type fields are required; all others are optional. If omitted, TTL defaults to 0 and Class defaults to IN. Omitting the optional fields is useful for creating the empty RDATA sections required for certain dynamic update operations.

The fields are case-insensitive, but starting each with uppercase is recommended.

print

$rr->print;

Prints the record to the standard output. Calls the string method to get the RR's string representation.

string

print $rr->string, "\n";

Returns a string representation of the RR. Calls the rdatastr method to get the RR-specific data.

rdatastr

$s = $rr->rdatastr;

Returns a string containing RR-specific data. Subclasses will need to implement this method.

name

$name = $rr->name;

Returns the record's domain name.

type

$type = $rr->type;

Returns the record's type.

class

$class = $rr->class;

Returns the record's class.

ttl

$ttl = $rr->ttl;

Returns the record's time-to-live (TTL).

rdlength

$rdlength = $rr->rdlength;

Returns the length of the record's data section.

rdata

$rdata = $rr->rdata

Returns the record's data section as binary data.

BUGS

This version of Net::DNS::RR does little sanity checking on user-created RR objects.

COPYRIGHT

Copyright (c) 1997-2002 Michael Fuhr.

Portions Copyright (c) 2002-2004 Chris Reinhardt.

Portions Copyright (c) 2005 Olaf Kolkman

All rights reserved. This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself.

EDNS0 extensions by Olaf Kolkman.

SEE ALSO

perl(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Packet, Net::DNS::Update, Net::DNS::Header, Net::DNS::Question, RFC 1035 Section 4.1.3