/ 
Net-DNS-0.59
/ check_soa
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

check_soa - Check nameservers for a domain in parallel

SYNOPSIS

check_soa [-d] [-t] [-v] domain [server]

DESCRIPTION

Each nameserver for the specified domain is queried for the relevant SOA record and the zone serial number printed.

Error reports are generated for nameservers which reply with non-authoritative, outdated or incorrect information.

SOA query packets are sent to the nameservers as rapidly as the underlying hardware will allow. The program waits for a response only when it is needed for analysis. Execution time is determined by the slowest nameserver.

This program is based on the check_soa idea described by Albitz and Liu.

OPTIONS AND ARGUMENTS

-d

Turn on resolver diagnostics.

-t

Ignore UDP datagram truncation.

-v

Verbose output including address records for each server.

domain

Fully qualified name of domain to be tested.

server

Name or list of IP addresses of DNS nameserver to be tested.

BUGS

The timeout code exploits the 4 argument form of select() function. This is not guaranteed to work in non-Unix environments.

COPYRIGHT

Copyright (c) 2003-2006, Dick Franks <rwfranks@acm.org>

This program is free software; you may use or redistribute it under the same terms as Perl itself.

SEE ALSO

Paul Albitz, Cricket Liu. DNS and BIND, 5th Edition. O'Reilly & Associates, 2006.

M. Andrews. Negative Caching of DNS Queries. RFC2308, IETF Network Working Group, 1998.

Tom Christiansen, Jon Orwant, Larry Wall. Programming Perl, 3rd Edition. O'Reilly & Associates, 2000.

R. Elz, R. Bush. Clarifications to the DNS Specification. RFC2181, IETF Network Working Group, 1997.

P. Mockapetris. Domain Names - Concepts and Facilities. RFC1034, IETF Network Working Group, 1987.