3.7 Low
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
4.3 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
0.006 Low
EPSS
Percentile
77.4%
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.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Alpine | edge-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.10-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.11-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.12-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.13-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.14-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.15-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.16-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.17-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
Alpine | 3.18-main | noarch | dnsmasq | < 2.83-r0 | UNKNOWN |
3.7 Low
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
4.3 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
0.006 Low
EPSS
Percentile
77.4%