DNS Server Cache Snooping Remote Information Disclosure

medium Nessus Plugin ID 12217


The remote DNS server is vulnerable to cache snooping attacks.


The remote DNS server responds to queries for third-party domains that do not have the recursion bit set.

This may allow a remote attacker to determine which domains have recently been resolved via this name server, and therefore which hosts have been recently visited.

For instance, if an attacker was interested in whether your company utilizes the online services of a particular financial institution, they would be able to use this attack to build a statistical model regarding company usage of that financial institution. Of course, the attack can also be used to find B2B partners, web-surfing patterns, external mail servers, and more.

Note: If this is an internal DNS server not accessible to outside networks, attacks would be limited to the internal network. This may include employees, consultants and potentially users on a guest network or WiFi connection if supported.


Contact the vendor of the DNS software for a fix.

See Also


Plugin Details

Severity: Medium

ID: 12217

File Name: dns_cache_sniffing.nasl

Version: 1.26

Type: remote

Family: DNS

Published: 4/27/2004

Updated: 4/7/2020

Risk Information

CVSS Score Rationale: Score from a more in depth analysis done by tenable


Risk Factor: Medium

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: manual


Risk Factor: Medium

Base Score: 5.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Vulnerability Information

Required KB Items: DNS/udp/53, dns_server/version