/ 
Net-DNS-0.66_03
/ Net::DNS::RR::HIP
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::HIP - DNS HIP resource record

SYNOPSIS

use Net::DNS::RR;

DESCRIPTION

This class implements the HIP RR (RFC5205)

METHODS

pkalgorithm

Returns or sets the public key algorithm field

hit

Returns or sets the hit in base16 representation.

hitbin

Returns or sets the binary representation of the the hit.

Using hit or hitbin to set the one of these attributes will update both attributes.

pubkey

Returns or sets the publick key in base64 representation.

pubkey

Returns or sets the binary representation of the the public key.

Using pubkey or pubkeybin to set the one of these attributes will update both attributes.

rendezvousservers

my $rendezvousservers=$hip->rendezvousservers();

Returns a reference to an array of rendezvous servers. The representation is in Perl's internal storage format i.e. without trailing dot.

$hip->rendezvousservers( [ qw|example.com  example.net| ] )

With a reference to an array as the argument this method will set the rendezvousservers.

NOTES

Since (multiline) base64 encoded publik keys may contain spaces string parsing of the HIP RR depends on rendevous server names containing at least one . (dot) in their domain name. Failure of string parsing will return an 'undef'.

The rdatastr method (and hence the string and print methods) return the rendezvousservers as fully qualified domain names.

COPYRIGHT

Copyright (c) 2009 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

perl(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Packet, Net::DNS::Header, Net::DNS::Question, Net::DNS::RR, RFC 5205