RHSA-2021:0153 - Security Advisory

Topic

An update for dnsmasq is now available for Red Hat Enterprise Linux 7.

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.

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.

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 Server 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• 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

CVEs

• CVE-2020-25684
• CVE-2020-25685
• CVE-2020-25686

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://access.redhat.com/security/vulnerabilities/RHSB-2021-001