[RHSA-2021:0155-01] Moderate: dnsmasq security update

Tue Jan 19 14:09:22 UTC 2021

An update for dnsmasq is now available for Red Hat Enterprise Linux 7.6
Extended Update Support.

Red Hat Product Security has rated this update as having a security impact
of Moderate. 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) - x86_64
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) - x86_64
Red Hat Enterprise Linux Server EUS (v. 7.6) - ppc64, ppc64le, s390x, x86_64
Red Hat Enterprise Linux Server Optional EUS (v. 7.6) - ppc64, ppc64le, s390x, x86_64
Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) - aarch64, ppc64le, s390x
Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) - aarch64, ppc64le, s390x

3. Description:

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

Security Fix(es):

* dnsmasq: loose address/port check in reply_query() makes forging replies
easier for an off-path attacker (CVE-2020-25684)

* dnsmasq: loose query name check in reply_query() makes forging replies
easier for an off-path attacker (CVE-2020-25685)

* dnsmasq: multiple queries forwarded for the same name makes forging
replies easier for an off-path attacker (CVE-2020-25686)

For more details about the security issue(s), including the impact, a CVSS
score, acknowledgments, and other related information, refer to the CVE
page(s) listed in the References section.

4. Solution:

For details on how to apply this update, which includes the changes
described in this advisory, refer to:

https://access.redhat.com/articles/11258

5. Bugs fixed (https://bugzilla.redhat.com/):

1889686 - CVE-2020-25684 dnsmasq: loose address/port check in reply_query() makes forging replies easier for an off-path attacker
1889688 - CVE-2020-25685 dnsmasq: loose query name check in reply_query() makes forging replies easier for an off-path attacker
1890125 - CVE-2020-25686 dnsmasq: multiple queries forwarded for the same name makes forging replies easier for an off-path attacker

6. Package List:

Red Hat Enterprise Linux ComputeNode EUS (v. 7.6):

Source:
dnsmasq-2.76-7.el7_6.2.src.rpm

x86_64:
dnsmasq-2.76-7.el7_6.2.x86_64.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.x86_64.rpm

Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6):

x86_64:
dnsmasq-debuginfo-2.76-7.el7_6.2.x86_64.rpm
dnsmasq-utils-2.76-7.el7_6.2.x86_64.rpm

Red Hat Enterprise Linux Server EUS (v. 7.6):

Source:
dnsmasq-2.76-7.el7_6.2.src.rpm

ppc64:
dnsmasq-2.76-7.el7_6.2.ppc64.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.ppc64.rpm

ppc64le:
dnsmasq-2.76-7.el7_6.2.ppc64le.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.ppc64le.rpm

s390x:
dnsmasq-2.76-7.el7_6.2.s390x.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.s390x.rpm

x86_64:
dnsmasq-2.76-7.el7_6.2.x86_64.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.x86_64.rpm

Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7):

Source:
dnsmasq-2.76-7.el7_6.2.src.rpm

aarch64:
dnsmasq-2.76-7.el7_6.2.aarch64.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.aarch64.rpm

ppc64le:
dnsmasq-2.76-7.el7_6.2.ppc64le.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.ppc64le.rpm

s390x:
dnsmasq-2.76-7.el7_6.2.s390x.rpm
dnsmasq-debuginfo-2.76-7.el7_6.2.s390x.rpm

Red Hat Enterprise Linux Server Optional EUS (v. 7.6):

ppc64:
dnsmasq-debuginfo-2.76-7.el7_6.2.ppc64.rpm
dnsmasq-utils-2.76-7.el7_6.2.ppc64.rpm

ppc64le:
dnsmasq-debuginfo-2.76-7.el7_6.2.ppc64le.rpm
dnsmasq-utils-2.76-7.el7_6.2.ppc64le.rpm

s390x:
dnsmasq-debuginfo-2.76-7.el7_6.2.s390x.rpm
dnsmasq-utils-2.76-7.el7_6.2.s390x.rpm

x86_64:
dnsmasq-debuginfo-2.76-7.el7_6.2.x86_64.rpm
dnsmasq-utils-2.76-7.el7_6.2.x86_64.rpm

Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7):

aarch64:
dnsmasq-debuginfo-2.76-7.el7_6.2.aarch64.rpm
dnsmasq-utils-2.76-7.el7_6.2.aarch64.rpm

ppc64le:
dnsmasq-debuginfo-2.76-7.el7_6.2.ppc64le.rpm
dnsmasq-utils-2.76-7.el7_6.2.ppc64le.rpm

s390x:
dnsmasq-debuginfo-2.76-7.el7_6.2.s390x.rpm
dnsmasq-utils-2.76-7.el7_6.2.s390x.rpm

These packages are GPG signed by Red Hat for security.  Our key and
details on how to verify the signature are available from
https://access.redhat.com/security/team/key/

7. References:

https://access.redhat.com/security/cve/CVE-2020-25684
https://access.redhat.com/security/cve/CVE-2020-25685
https://access.redhat.com/security/cve/CVE-2020-25686
https://access.redhat.com/security/updates/classification/#moderate
https://access.redhat.com/security/vulnerabilities/RHSB-2021-001

8. Contact:

The Red Hat security contact is <secalert at redhat.com>. More contact
details at https://access.redhat.com/security/team/contact/

Copyright 2021 Red Hat, Inc.
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