Thekelleys: >> Dnsmasq >> 2.76 Security Vulnerabilities
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.
CVSS Score
5.9
EPSS Score
0.86
Published
2021-01-20
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.
CVSS Score
3.7
EPSS Score
0.04
Published
2021-01-20
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.
CVSS Score
3.7
EPSS Score
0.022
Published
2021-01-20
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.
CVSS Score
3.7
EPSS Score
0.027
Published
2020-01-07
A vulnerability was found in the implementation of DNSSEC in Dnsmasq up to and including 2.78. Wildcard synthesized NSEC records could be improperly interpreted to prove the non-existence of hostnames that actually exist.
CVSS Score
7.5
EPSS Score
0.026
Published
2018-01-23
Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DNS response.
CVSS Score
9.8
EPSS Score
0.849
Published
2017-10-04
Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted IPv6 router advertisement request.
CVSS Score
9.8
EPSS Score
0.933
Published
2017-10-03
Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DHCPv6 request.
CVSS Score
9.8
EPSS Score
0.836
Published
2017-10-03
dnsmasq before 2.78, when configured as a relay, allows remote attackers to obtain sensitive memory information via vectors involving handling DHCPv6 forwarded requests.
CVSS Score
5.9
EPSS Score
0.675
Published
2017-10-03
Memory leak in dnsmasq before 2.78, when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a denial of service (memory consumption) via vectors involving DNS response creation.
CVSS Score
7.5
EPSS Score
0.843
Published
2017-10-03