Synopsis

Important: dnsmasq security update

Type/Severity

Security Advisory: Important

Topic

An update for dnsmasq is now available for Red Hat Enterprise Linux 8.1 Extended Update Support.

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

Description

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

Security Fix(es):

• dnsmasq: heap-based buffer overflow in sort_rrset() when DNSSEC is enabled (CVE-2020-25681)
• dnsmasq: buffer overflow in extract_name() due to missing length check when DNSSEC is enabled (CVE-2020-25682)
• dnsmasq: heap-based buffer overflow with large memcpy in get_rdata() when DNSSEC is enabled (CVE-2020-25683)
• 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)
• dnsmasq: heap-based buffer overflow with large memcpy in sort_rrset() when DNSSEC is enabled (CVE-2020-25687)

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.

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

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 8.1 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 8.1 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 8.1 ppc64le
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 8.1 aarch64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 8.1 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 8.1 x86_64

Fixes

• BZ - 1881875 - CVE-2020-25681 dnsmasq: heap-based buffer overflow in sort_rrset() when DNSSEC is enabled
• BZ - 1882014 - CVE-2020-25682 dnsmasq: buffer overflow in extract_name() due to missing length check when DNSSEC is enabled
• BZ - 1882018 - CVE-2020-25683 dnsmasq: heap-based buffer overflow with large memcpy in get_rdata() when DNSSEC is enabled
• BZ - 1889686 - CVE-2020-25684 dnsmasq: loose address/port check in reply_query() makes forging replies easier for an off-path attacker
• BZ - 1889688 - CVE-2020-25685 dnsmasq: loose query name check in reply_query() makes forging replies easier for an off-path attacker
• BZ - 1890125 - CVE-2020-25686 dnsmasq: multiple queries forwarded for the same name makes forging replies easier for an off-path attacker
• BZ - 1891568 - CVE-2020-25687 dnsmasq: heap-based buffer overflow with large memcpy in sort_rrset() when DNSSEC is enabled

CVEs

• CVE-2020-25681
• CVE-2020-25682
• CVE-2020-25683
• CVE-2020-25684
• CVE-2020-25685
• CVE-2020-25686
• CVE-2020-25687

References