A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other systems.

The remote Redhat Enterprise Linux 7 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - dnsmasq: unchecked return value of the setup_reply() function (CVE-2015-3294)

  - dnsmasq: insecure default configuration makes it an open resolver (CVE-2020-14312)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

According to the versions of the dnsmasq packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the dnsmasq packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the dnsmasq packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

  - A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given     network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to     find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply     and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest     threat from this vulnerability is to data integrity. (CVE-2021-3448)

  - A single-byte, non-arbitrary write/use-after-free flaw was found in dnsmasq. This flaw allows an attacker     who sends a crafted packet processed by dnsmasq, potentially causing a denial of service. (CVE-2022-0934)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the dnsmasq package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the dnsmasq package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote SUSE Linux SUSE15 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2021:1426-1 advisory.

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

  - A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given     network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to     find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply     and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest     threat from this vulnerability is to data integrity. (CVE-2021-3448)

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

The remote SUSE Linux SUSE15 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2021:3530-1 advisory.

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

  - A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given     network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to     find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply     and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest     threat from this vulnerability is to data integrity. (CVE-2021-3448)

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

The remote SUSE Linux SLED15 / SLES15 / SLES_SAP15 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3530-1 advisory.

  - A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and     in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from     addresses outside of its local subnet. In particular, the option `local-service` is not enabled. Running     dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other     systems. (CVE-2020-14312)

  - A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given     network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to     find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply     and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest     threat from this vulnerability is to data integrity. (CVE-2021-3448)

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

According to the versions of the dnsmasq packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in the default configuration of     dnsmasq, as shipped with Fedora and Red Hat Enterprise     Linux, where it listens on any interface and accepts     queries from addresses outside of its local subnet. In     particular, the option `local-service` is not enabled.
    Running dnsmasq in this manner may inadvertently make     it an open resolver accessible from any address on the     internet. This flaw allows an attacker to conduct a     Distributed Denial of Service (DDoS) against other     systems.(CVE-2020-14312)

  - A flaw was found in dnsmasq. A heap-based buffer     overflow was discovered in dnsmasq when DNSSEC is     enabled and before it validates the received DNS     entries. This flaw allows a remote attacker, who can     create valid DNS replies, to cause an overflow in a     heap-allocated memory. This flaw is caused by the lack     of length checks in rfc1035.c:extract_name(), which     could be abused to make the code execute memcpy() with     a negative size in sort_rrset() and cause a crash in     dnsmasq, resulting in a denial of service. The highest     threat from this vulnerability is to system     availability.(CVE-2020-25687)

  - A flaw was found in dnsmasq. When receiving a query,     dnsmasq does not check for an existing pending request     for the same name and forwards a new request. By     default, a maximum of 150 pending queries can be sent     to upstream servers, so there can be at most 150     queries for the same name. This flaw allows an off-path     attacker on the network to substantially reduce the     number of attempts that it would have to perform to     forge a reply and have it accepted by dnsmasq. This     issue is mentioned in the 'Birthday Attacks' section of     RFC5452. If chained with CVE-2020-25684, the attack     complexity of a successful attack is reduced. The     highest threat from this vulnerability is to data     integrity.(CVE-2020-25686)

  - A flaw was found in dnsmasq. A heap-based buffer     overflow was discovered in dnsmasq when DNSSEC is     enabled and before it validates the received DNS     entries. A remote attacker, who can create valid DNS     replies, could use this flaw to cause an overflow in a     heap-allocated memory. This flaw is caused by the lack     of length checks in rfc1035.c:extract_name(), which     could be abused to make the code execute memcpy() with     a negative size in get_rdata() and cause a crash in     dnsmasq, resulting in a denial of service. The highest     threat from this vulnerability is to system     availability.(CVE-2020-25685)

  - A flaw was found in dnsmasq. 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)

  - A flaw was found in dnsmasq. A heap-based buffer     overflow was discovered in dnsmasq when DNSSEC is     enabled and before it validates the received DNS     entries. A remote attacker, who can create valid DNS     replies, could use this flaw to cause an overflow in a     heap-allocated memory. This flaw is caused by the lack     of length checks in rfc1035.c:extract_name(), which     could be abused to make the code execute memcpy() with     a negative size in get_rdata() and cause a crash in     dnsmasq, resulting in a denial of service. The highest     threat from this vulnerability is to system     availability.(CVE-2020-25683)

  - A flaw was found in dnsmasq. A buffer overflow     vulnerability was discovered in the way dnsmasq extract     names from DNS packets before validating them with     DNSSEC data. An attacker on the network, who can create     valid DNS replies, could use this flaw to cause an     overflow with arbitrary data in a heap-allocated     memory, possibly executing code on the machine. The     flaw is in the rfc1035.c:extract_name() function, which     writes data to the memory pointed by name assuming     MAXDNAME*2 bytes are available in the buffer. However,     in some code execution paths, it is possible     extract_name() gets passed an offset from the base     buffer, thus reducing, in practice, the number of     available bytes that can be written in the buffer. The     highest threat from this vulnerability is to data     confidentiality and integrity as well as system     availability.(CVE-2020-25682)

  - A flaw was found in dnsmasq. A heap-based buffer     overflow was discovered in the way RRSets are sorted     before validating with DNSSEC data. An attacker on the     network, who can forge DNS replies such as that they     are accepted as valid, could use this flaw to cause a     buffer overflow with arbitrary data in a heap memory     segment, possibly executing code on the machine. The     highest threat from this vulnerability is to data     confidentiality and integrity as well as system     availability.(CVE-2020-25681)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Make dnsmasq listen in default configuration only on localhost device.
bind-dynamic is not required, because localhost should not change during the life of dnsmasq.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

A flaw was found in the default configuration of dnsmasq, as shipped with Fedora and Red Hat Enterprise Linux, where it listens on any interface and accepts queries from addresses outside of its local subnet. In particular, the option `local-service` is not enabled.
Running dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other systems. (CVE-2020-14312)

Change dnsmasq default configuration to listen only on localhost. If it should answer local network, configuration has to be modified.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
198892	RHEL 7 : dnsmasq (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	medium
197281	EulerOS Virtualization 3.0.6.0 : dnsmasq (EulerOS-SA-2024-1678)	Nessus	Huawei Local Security Checks	medium
191877	EulerOS 2.0 SP8 : dnsmasq (EulerOS-SA-2024-1261)	Nessus	Huawei Local Security Checks	medium
175203	EulerOS Virtualization 3.0.2.0 : dnsmasq (EulerOS-SA-2023-1732)	Nessus	Huawei Local Security Checks	medium
169858	EulerOS Virtualization 2.9.1 : dnsmasq (EulerOS-SA-2023-1189)	Nessus	Huawei Local Security Checks	medium
169801	EulerOS Virtualization 2.9.0 : dnsmasq (EulerOS-SA-2023-1219)	Nessus	Huawei Local Security Checks	medium
169399	EulerOS Virtualization 2.10.0 : dnsmasq (EulerOS-SA-2022-2901)	Nessus	Huawei Local Security Checks	medium
169362	EulerOS Virtualization 2.10.1 : dnsmasq (EulerOS-SA-2022-2927)	Nessus	Huawei Local Security Checks	medium
167401	EulerOS 2.0 SP9 : dnsmasq (EulerOS-SA-2022-2725)	Nessus	Huawei Local Security Checks	medium
167359	EulerOS 2.0 SP9 : dnsmasq (EulerOS-SA-2022-2760)	Nessus	Huawei Local Security Checks	medium
166872	EulerOS 2.0 SP10 : dnsmasq (EulerOS-SA-2022-2646)	Nessus	Huawei Local Security Checks	medium
166819	EulerOS 2.0 SP10 : dnsmasq (EulerOS-SA-2022-2678)	Nessus	Huawei Local Security Checks	medium
154756	openSUSE 15 Security Update : dnsmasq (openSUSE-SU-2021:1426-1)	Nessus	SuSE Local Security Checks	medium
154665	openSUSE 15 Security Update : dnsmasq (openSUSE-SU-2021:3530-1)	Nessus	SuSE Local Security Checks	medium
154646	SUSE SLED15 / SLES15 Security Update : dnsmasq (SUSE-SU-2021:3530-1)	Nessus	SuSE Local Security Checks	medium
147133	EulerOS Virtualization for ARM 64 3.0.6.0 : dnsmasq (EulerOS-SA-2021-1551)	Nessus	Huawei Local Security Checks	high
141527	Fedora 32 : dnsmasq (2020-756b92a093)	Nessus	Fedora Local Security Checks	medium
141300	Fedora 33 : dnsmasq (2020-54760174b6)	Nessus	Fedora Local Security Checks	medium
139337	Amazon Linux 2 : dnsmasq (ALAS-2020-1469)	Nessus	Amazon Linux Local Security Checks	medium
138531	Fedora 31 : dnsmasq (2020-329859eff4)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2020-14312

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

high

medium

medium

medium

medium