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

DNSHash::MX - Put DNS MX queries in a hash lookup format

SYNOPSIS

require DNSHash;

tie %DNS, "DNSHash::MX", <preload>, <cachedb>, <usettl>

$mxhostname = $DNS{"host.do.main"};

DESCRIPTION

This implements DNS MX lookups as a tied hash. It takes the first answer at the lowest priority (like sendmail would to).

If the file <preload> is defined, the hash is preloaded with the hostname/mxhostname pairs found in this file. Format is

mxhostname   hostname

Assignments to this hash are added to the preload lookup. You can delete preload lookups by delete()ing the entry.

Lookups are cached once done if <cachedb> is defined.

Cache entries are held for <usettl> seconds unless <usettl> undefined, in which case the TTL of the record is used in each case.

You can clear the cache by removing <cachedb>. If you want to clear a particular lookup in the cache, use delete().

each() on these hashes only walks the preload.

NAME

DNSHash - Put DNS hostname/ip queries in a hash lookup format

SYNOPSIS

require DNSHash;

tie %DNS, "DNSHash", <preload>, <cachedb>, <usettl>

$hostname = $DNS{"a.b.c.d"}; $ip = $DNS{"host.do.main"};

$DNS{"host.do.main"} = $realip;

DESCRIPTION

This implements DNS A and PTR record lookup as a tied hash.

If the file <preload> is defined, the hash is preloaded with the hostname/ip pairs found in the file (format is like /etc/hosts).

Assignments to this hash are added to the preload lookup. You can delete preload lookups by delete()ing the entry.

Lookups are cached once done if <cachedb> is defined.

Cache entries are held for <usettl> seconds unless <usettl> undefined, in which case the TTL of the record is used in each case.

You can clear the cache by removing <cachedb>. If you want to clear a particular lookup in the cache, use delete().

each() on these hashes only walks the preload.