/ 
Net-DNS-0.66_01
/ Net::DNS::RR::NSAP
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::NSAP - DNS NSAP resource record

SYNOPSIS

use Net::DNS::RR;

DESCRIPTION

Class for DNS Network Service Access Point (NSAP) resource records.

METHODS

idp

print "idp = ", $rr->idp, "\n";

Returns the RR's initial domain part (the AFI and IDI fields).

dsp

print "dsp = ", $rr->dsp, "\n";

Returns the RR's domain specific part (the DFI, AA, Rsvd, RD, Area, ID, and SEL fields).

afi

print "afi = ", $rr->afi, "\n";

Returns the RR's authority and format identifier. Net::DNS currently supports only AFI 47 (GOSIP Version 2).

idi

print "idi = ", $rr->idi, "\n";

Returns the RR's initial domain identifier.

dfi

print "dfi = ", $rr->dfi, "\n";

Returns the RR's DSP format identifier.

aa

print "aa = ", $rr->aa, "\n";

Returns the RR's administrative authority.

rsvd

print "rsvd = ", $rr->rsvd, "\n";

Returns the RR's reserved field.

rd

print "rd = ", $rr->rd, "\n";

Returns the RR's routing domain identifier.

area

print "area = ", $rr->area, "\n";

Returns the RR's area identifier.

id

print "id = ", $rr->id, "\n";

Returns the RR's system identifier.

sel

print "sel = ", $rr->sel, "\n";

Returns the RR's NSAP selector.

NOTE

COPYRIGHT

Copyright (c) 1997-2002 Michael Fuhr.

Portions Copyright (c) 2002-2004 Chris Reinhardt.

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 1706.