CVE-2020-25686 | Date: (C)2021-01-21 (M)2023-12-22 |
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.
CVSS Score and Metrics +CVSS Score and Metrics -CVSS V3 Severity: | CVSS V2 Severity: |
CVSS Score : 3.7 | CVSS Score : 4.3 |
Exploit Score: 2.2 | Exploit Score: 8.6 |
Impact Score: 1.4 | Impact Score: 2.9 |
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CVSS V3 Metrics: | CVSS V2 Metrics: |
Attack Vector: NETWORK | Access Vector: NETWORK |
Attack Complexity: HIGH | Access Complexity: MEDIUM |
Privileges Required: NONE | Authentication: NONE |
User Interaction: NONE | Confidentiality: NONE |
Scope: UNCHANGED | Integrity: PARTIAL |
Confidentiality: NONE | Availability: NONE |
Integrity: LOW | |
Availability: NONE | |
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