/ 
Net-DNS-0.66_04
/ Net::DNS::RR::APL
Security Advisories (2)
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::APL - DNS APL resource record

SYNOPSIS

use Net::DNS::RR;

DESCRIPTION

This is an RR type for address prefix lists. Please see the RFC3123 for details.

METHODS

applist

Returns an array of Net::DNS::APL::ApItem objects.

Each ApItem objecst contains the following attribute that can be accessed and set using methods of the same name: addressfamily, prefix, negation, address

foreach my $ap ($apl->aplist()){
   	print $ap->negation()?"!":"";
  	print $ap->addressfamily().":";
  	print $ap->address();
  	print $ap->prefix(). " ";
  }

In addition the Net::DNS::APL::ApItem objects can be printed using the string method.

foreach my $ap ($apl->aplist())
          print $ap->string."\n";
}

COPYRIGHT

Copyright (c) 2008 Olaf Kolkman (NLnet Labs)

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

SEE ALSO

Net::DNS::RR::APL::ApItem, perl(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Packet, Net::DNS::Header, Net::DNS::Question, Net::DNS::RR, RFC 3123