RHEL 7 : dnsmasq (RHSA-2017:2837)

critical Nessus Plugin ID 103629


The remote Red Hat host is missing one or more security updates.


An update for dnsmasq is now available for Red Hat Enterprise Linux 7.2 Extended Update Support and Red Hat Enterprise Linux 7.3 Extended Update Support.

Red Hat Product Security has rated this update as having a security impact of Critical. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The dnsmasq packages contain Dnsmasq, a lightweight DNS (Domain Name Server) forwarder and DHCP (Dynamic Host Configuration Protocol) server.

Security Fix(es) :

* A heap buffer overflow was found in dnsmasq in the code responsible for building DNS replies. An attacker could send crafted DNS packets to dnsmasq which would cause it to crash or, potentially, execute arbitrary code. (CVE-2017-14491)

* A heap buffer overflow was discovered in dnsmasq in the IPv6 router advertisement (RA) handling code. An attacker on the local network segment could send crafted RAs to dnsmasq which would cause it to crash or, potentially, execute arbitrary code. This issue only affected configurations using one of these options: enable-ra, ra-only, slaac, ra-names, ra-advrouter, or ra-stateless.

* A stack-based buffer overflow was found in dnsmasq in the DHCPv6 code. An attacker on the local network could send a crafted DHCPv6 request to dnsmasq which would cause it to a crash or, potentially, execute arbitrary code. (CVE-2017-14493)

* An information leak was found in dnsmasq in the DHCPv6 relay code.
An attacker on the local network could send crafted DHCPv6 packets to dnsmasq causing it to forward the contents of process memory, potentially leaking sensitive data. (CVE-2017-14494)

Red Hat would like to thank Felix Wilhelm (Google Security Team), Fermin J. Serna (Google Security Team), Gabriel Campana (Google Security Team), Kevin Hamacher (Google Security Team), and Ron Bowes (Google Security Team) for reporting these issues.


Update the affected dnsmasq, dnsmasq-debuginfo and / or dnsmasq-utils packages.

See Also







Plugin Details

Severity: Critical

ID: 103629

File Name: redhat-RHSA-2017-2837.nasl

Version: 3.17

Type: local

Agent: unix

Published: 10/3/2017

Updated: 5/8/2020

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent

Risk Information


Risk Factor: High

Score: 7.4


Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:dnsmasq, p-cpe:/a:redhat:enterprise_linux:dnsmasq-debuginfo, p-cpe:/a:redhat:enterprise_linux:dnsmasq-utils, cpe:/o:redhat:enterprise_linux:7.2, cpe:/o:redhat:enterprise_linux:7.3

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/2/2017

Vulnerability Publication Date: 10/3/2017

Exploitable With

Core Impact

Reference Information

CVE: CVE-2017-14491, CVE-2017-14492, CVE-2017-14493, CVE-2017-14494

RHSA: 2017:2837

IAVA: 2017-A-0284-S