Simon Kelley reports :

There are broadly two sets of problems. The first is subtle errors in dnsmasq's protections against the chronic weakness of the DNS protocol to cache-poisoning attacks; the Birthday attack, Kaminsky, etc.[...]

the second set of errors is a good old fashioned buffer overflow in dnsmasq's DNSSEC code. If DNSSEC validation is enabled, an installation is at risk.

This update for dnsmasq fixes the following issues :

  - bsc#1177077: Fixed DNSpooq vulnerabilities

  - CVE-2020-25684, CVE-2020-25685, CVE-2020-25686: Fixed     multiple Cache Poisoning attacks.

  - CVE-2020-25681, CVE-2020-25682, CVE-2020-25683,     CVE-2020-25687: Fixed multiple potential Heap-based     overflows when DNSSEC is enabled.

  - Retry query to other servers on receipt of SERVFAIL     rcode (bsc#1176076)

This update was imported from the SUSE:SLE-15-SP1:Update update project.

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:0154 advisory.

    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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:0156 advisory.

    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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Scientific Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the SLSA-2021:0153-1 advisory.

  - 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)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq     checks in the forward.c:reply_query() if the reply destination address/port is used by the pending     forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query,     substantially reducing the number of attempts an attacker on the network would have to perform to forge a     reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's     attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache     Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful     attack is reduced. The highest threat from this vulnerability is to data integrity. (CVE-2020-25684)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Redhat Enterprise Linux 8 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2021:0401 advisory.

    The redhat-virtualization-host packages provide the Red Hat Virtualization Host. These packages include     redhat-release-virtualization-host, ovirt-node, and rhev-hypervisor. Red Hat Virtualization Hosts (RHVH)     are installed using a special build of Red Hat Enterprise Linux with only the packages required to host     virtual machines. RHVH features a Cockpit user interface for monitoring the host's resources and     performing administrative tasks.

    Security Fix(es):

    * sudo: Heap buffer overflow in argument parsing (CVE-2021-3156)

    * 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.

    Bug Fix(es):

    * Previously, the Red Hat Virtualization Host (RHV-H) repository (rhvh-4-for-rhel-8-x86_64-rpms) did not     include the libsmbclient package, which is a dependency for the sssd-ad package. Consequently, the sssd-ad     package failed to install.

    With this update, the libsmbclient is now in the RHV-H repository, and sssd-ad now installs on RHV-H.
    (BZ#1868967)

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Published	Updated	Severity
145236	FreeBSD : dnsmasq -- DNS cache poisoning, and DNSSEC buffer overflow, vulnerabilities (5b5cf6e5-5b51-11eb-95ac-7f9491278677)	Nessus	FreeBSD Local Security Checks	1/21/2021	12/5/2022	high
145295	openSUSE Security Update : dnsmasq (openSUSE-2021-129)	Nessus	SuSE Local Security Checks	1/25/2021	12/5/2022	high
145079	RHEL 7 : dnsmasq (RHSA-2021:0154)	Nessus	Red Hat Local Security Checks	1/19/2021	11/7/2024	low
145083	RHEL 7 : dnsmasq (RHSA-2021:0156)	Nessus	Red Hat Local Security Checks	1/19/2021	11/7/2024	low
145438	Scientific Linux Security Update : dnsmasq on SL7.x x86_64 (2021:0153)	Nessus	Scientific Linux Local Security Checks	1/26/2021	12/5/2022	low
251632	Linux Distros Unpatched Vulnerability : CVE-2020-25684	Nessus	Misc.	8/18/2025	8/19/2025	low
146094	RHEL 8 : Red Hat Virtualization Host security update [ovirt-4.4.4] (Important) (RHSA-2021:0401)	Nessus	Red Hat Local Security Checks	2/3/2021	11/7/2024	high

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