GLSA-200708-13 : BIND: Weak random number generation

medium Nessus Plugin ID 25919

Synopsis

The remote Gentoo host is missing one or more security-related patches.

Description

The remote host is affected by the vulnerability described in GLSA-200708-13 (BIND: Weak random number generation)

Amit Klein from Trusteer reported that the random number generator of ISC BIND leads, half the time, to predictable (1 chance to 8) query IDs in the resolver routine or in zone transfer queries (CVE-2007-2926).
Additionally, the default configuration file has been strengthen with respect to the allow-recursion{} and the allow-query{} options (CVE-2007-2925).
Impact :

A remote attacker can use this weakness by sending queries for a domain he handles to a resolver (directly to a recursive server, or through another process like an email processing) and then observing the resulting IDs of the iterative queries. The attacker will half the time be able to guess the next query ID, then perform cache poisoning by answering with those guessed IDs, while spoofing the UDP source address of the reply. Furthermore, with empty allow-recursion{} and allow-query{} options, the default configuration allowed anybody to make recursive queries and query the cache.
Workaround :

There is no known workaround at this time for the random generator weakness. The allow-recursion{} and allow-query{} options should be set to trusted hosts only in /etc/bind/named.conf, thus preventing several security risks.

Solution

All ISC BIND users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose '>=net-dns/bind-9.4.1_p1'

See Also

https://security.gentoo.org/glsa/200708-13

Plugin Details

Severity: Medium

ID: 25919

File Name: gentoo_GLSA-200708-13.nasl

Version: 1.17

Type: local

Published: 8/21/2007

Updated: 1/6/2021

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.5

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

Vulnerability Information

CPE: cpe:/o:gentoo:linux, p-cpe:/a:gentoo:linux:bind

Required KB Items: Host/local_checks_enabled, Host/Gentoo/release, Host/Gentoo/qpkg-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/18/2007

Vulnerability Publication Date: 7/24/2007

Reference Information

CVE: CVE-2007-2925, CVE-2007-2926

GLSA: 200708-13