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)

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

The remote host is affected by the vulnerability described in GLSA-202101-17 (Dnsmasq: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Dnsmasq. Please review       the references below for details.
  Impact :

    An attacker, by sending specially crafted DNS replies, could possibly       execute arbitrary code with the privileges of the process, perform a       cache poisoning attack or cause a Denial of Service condition.
  Workaround :

    There is no known workaround at this time.

An update of the dnsmasq package has been released.

The remote NewStart CGSL host, running version MAIN 6.02, has dnsmasq packages installed that are affected by multiple vulnerabilities:

  - A flaw was found in dnsmasq before version 2.83. 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)

  - A flaw was found in dnsmasq before 2.83. 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 before version 2.83. 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 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)

  - A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq     checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a     weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1     when it is) this flaw allows an off-path attacker to find several different domains all having the same     hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it     accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the     attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache     Poisoning attack. 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-2020-25685)

  - A flaw was found in dnsmasq before version 2.83. 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 before version 2.83. 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)

Note that Nessus has not tested for this issue 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 installation on the remote host is affected by the following vulnerabilities :

  - 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)

  - 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 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. 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. 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 getting a reply from     a forwarded query, dnsmasq checks in     forward.c:reply_query(), which is the forwarded query     that matches the reply, by only using a weak hash of     the query name. Due to the weak hash (CRC32 when     dnsmasq is compiled without DNSSEC, SHA-1 when it is)     this flaw allows an off-path attacker to find several     different domains all having the same hash,     substantially reducing the number of attempts they     would have to perform to forge a reply and get it     accepted by dnsmasq. This is in contrast with RFC5452,     which specifies that the query name is one of the     attributes of a query that must be used to match a     reply. This flaw could be abused to perform a DNS Cache     Poisoning attack. 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-2020-25685)

  - 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)

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 SLES11 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:14603-1 advisory.

  - A vulnerability was found in dnsmasq before version 2.81, where the memory leak allows remote attackers to     cause a denial of service (memory consumption) via vectors involving DHCP response creation.
    (CVE-2019-14834)

  - A flaw was found in dnsmasq before version 2.83. 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)

  - A flaw was found in dnsmasq before 2.83. 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 before version 2.83. 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 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)

  - A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq     checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a     weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1     when it is) this flaw allows an off-path attacker to find several different domains all having the same     hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it     accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the     attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache     Poisoning attack. 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-2020-25685)

  - A flaw was found in dnsmasq before version 2.83. 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 before version 2.83. 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)

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

The remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has dnsmasq packages installed that are affected by multiple vulnerabilities:

  - The DNS protocol, as implemented in (1) BIND 8 and 9 before 9.5.0-P1, 9.4.2-P1, and 9.3.5-P1; (2)     Microsoft DNS in Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP1 and SP2; and other implementations     allow remote attackers to spoof DNS traffic via a birthday attack that uses in-bailiwick referrals to     conduct cache poisoning against recursive resolvers, related to insufficient randomness of DNS transaction     IDs and source ports, aka DNS Insufficient Socket Entropy Vulnerability or the Kaminsky bug.
    (CVE-2008-1447)

  - Heap-based buffer overflow in the tftp_request function in tftp.c in dnsmasq before 2.50, when --enable-     tftp is used, might allow remote attackers to execute arbitrary code via a long filename in a TFTP packet,     as demonstrated by a read (aka RRQ) request. (CVE-2009-2957)

  - The tftp_request function in tftp.c in dnsmasq before 2.50, when --enable-tftp is used, allows remote     attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a TFTP read (aka     RRQ) request with a malformed blksize option. (CVE-2009-2958)

  - Dnsmasq before 2.66test2, when used with certain libvirt configurations, replies to queries from     prohibited interfaces, which allows remote attackers to cause a denial of service (traffic amplification)     via spoofed TCP based DNS queries. NOTE: this vulnerability exists because of an incomplete fix for     CVE-2012-3411. (CVE-2013-0198)

  - 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)

  - A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq     checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a     weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1     when it is) this flaw allows an off-path attacker to find several different domains all having the same     hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it     accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the     attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache     Poisoning attack. 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-2020-25685)

  - A flaw was found in dnsmasq before version 2.83. 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)

  - An issue was discovered in Dnsmasq before 2.90. The default maximum EDNS.0 UDP packet size was set to 4096     but should be 1232 because of DNS Flag Day 2020. (CVE-2023-28450)

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
145199	SUSE SLES15 Security Update : dnsmasq (SUSE-SU-2021:0162-1)	Nessus	SuSE Local Security Checks	1/20/2021	12/7/2022	high
145282	GLSA-202101-17 : Dnsmasq: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	1/25/2021	12/6/2022	high
145420	Photon OS 1.0: Dnsmasq PHSA-2021-1.0-0356	Nessus	PhotonOS Local Security Checks	1/26/2021	12/5/2022	high
147341	NewStart CGSL MAIN 6.02 : dnsmasq Multiple Vulnerabilities (NS-SA-2021-0091)	Nessus	NewStart CGSL Local Security Checks	3/10/2021	12/5/2022	high
147517	EulerOS Virtualization 3.0.6.6 : dnsmasq (EulerOS-SA-2021-1469)	Nessus	Huawei Local Security Checks	3/10/2021	1/11/2024	high
150612	SUSE SLES11 Security Update : dnsmasq (SUSE-SU-2021:14603-1)	Nessus	SuSE Local Security Checks	6/10/2021	12/6/2022	high
193540	NewStart CGSL CORE 5.04 / MAIN 5.04 : dnsmasq Multiple Vulnerabilities (NS-SA-2024-0011)	Nessus	NewStart CGSL Local Security Checks	4/18/2024	4/19/2024	medium

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