/ 
Net-DNS-0.81_01
/ Net::DNS::Mailbox
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::Mailbox - DNS mailbox representation

SYNOPSIS

use Net::DNS::Mailbox;

$mailbox = new Net::DNS::Mailbox('user@example.com');
$address = $mailbox->address;

DESCRIPTION

The Net::DNS::Mailbox module implements a subclass of DNS domain name objects representing the DNS coded form of RFC822 mailbox address.

METHODS

new

$mailbox = new Net::DNS::Mailbox('John.Doe@example.com');
$mailbox = new Net::DNS::Mailbox('John Doe <j.doe@example.com>');

Creates a mailbox object which represents the DNS domain encoded form of the mail address specified by the character string argument.

The argument string consists of printable characters from the 7-bit ASCII repertoire.

address

$address = $mailbox->address;

Returns a character string containing the RFC822 mailbox address corresponding to the encoded domain name representation described in RFC1035 section 8.

DOMAIN NAME COMPRESSION AND CANONICALISATION

The Net::DNS::Mailbox1035 and Net::DNS::Mailbox2535 subclass packages implement RFC1035 domain name compression and RFC2535 canonicalisation.

COPYRIGHT

Copyright (c)2009,2012 Dick Franks.

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, Net::DNS, Net::DNS::DomainName, RFC822, RFC1035, RFC5322