CVE-2020-25686
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2020-25686
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2020-25686.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2020-25686
- Downstream
- Related
- Published
- 2021-01-20T17:15:13Z
- Modified
- 2025-09-19T12:13:41.983458Z
- Severity
-
- 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
- Summary
- [none]
- Details
-
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.
- References
-
- https://bugzilla.redhat.com/show_bug.cgi?id=1890125
- https://security.gentoo.org/glsa/202101-17
- https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61
- https://www.debian.org/security/2021/dsa-4844
- https://www.jsof-tech.com/disclosures/dnspooq/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
- https://security.alpinelinux.org/vuln/CVE-2020-25686
Affected packages
Alpine:v3.10
dnsmasq
Package
- Name
- dnsmasq
- Purl
- pkg:apk/alpine/dnsmasq?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed2.83-r0
Affected versions
2.*
2.46-r0
2.47-r0
2.49-r0
2.50-r0
2.50-r1
2.51-r0
2.52-r0
2.52-r1
2.55-r0
2.57-r0
2.58-r0
2.59-r0
2.59-r1
2.60-r0
2.61-r0
2.62-r0
2.63-r0
2.64-r0
2.65-r0
2.66-r0
2.66-r1
2.66-r2
2.67-r0
2.68-r0
2.69-r0
2.70-r0
2.71-r0
2.72-r0
2.72-r1
2.73-r0
2.75-r0
2.75-r1
2.75-r2
2.76-r0
2.76-r1
2.76-r2
2.76-r3
2.76-r4
2.77-r0
2.78-r0
2.78-r1
2.78-r2
2.79-r0
2.79-r1
2.79-r2
2.80-r0
2.80-r1
2.80-r2
2.80-r3
2.80-r4
Alpine:v3.11
dnsmasq
Package
- Name
- dnsmasq
- Purl
- pkg:apk/alpine/dnsmasq?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed2.83-r0
Affected versions
2.*
2.46-r0
2.47-r0
2.49-r0
2.50-r0
2.50-r1
2.51-r0
2.52-r0
2.52-r1
2.55-r0
2.57-r0
2.58-r0
2.59-r0
2.59-r1
2.60-r0
2.61-r0
2.62-r0
2.63-r0
2.64-r0
2.65-r0
2.66-r0
2.66-r1
2.66-r2
2.67-r0
2.68-r0
2.69-r0
2.70-r0
2.71-r0
2.72-r0
2.72-r1
2.73-r0
2.75-r0
2.75-r1
2.75-r2
2.76-r0
2.76-r1
2.76-r2
2.76-r3
2.76-r4
2.77-r0
2.78-r0
2.78-r1
2.78-r2
2.79-r0
2.79-r1
2.79-r2
2.80-r0
2.80-r1
2.80-r2
2.80-r3
2.80-r4
2.80-r5
Alpine:v3.12
dnsmasq
Package
- Name
- dnsmasq
- Purl
- pkg:apk/alpine/dnsmasq?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed2.83-r0
Affected versions
2.*
2.46-r0
2.47-r0
2.49-r0
2.50-r0
2.50-r1
2.51-r0
2.52-r0
2.52-r1
2.55-r0
2.57-r0
2.58-r0
2.59-r0
2.59-r1
2.60-r0
2.61-r0
2.62-r0
2.63-r0
2.64-r0
2.65-r0
2.66-r0
2.66-r1
2.66-r2
2.67-r0
2.68-r0
2.69-r0
2.70-r0
2.71-r0
2.72-r0
2.72-r1
2.73-r0
2.75-r0
2.75-r1
2.75-r2
2.76-r0
2.76-r1
2.76-r2
2.76-r3
2.76-r4
2.77-r0
2.78-r0
2.78-r1
2.78-r2
2.79-r0
2.79-r1
2.79-r2
2.80-r0
2.80-r1
2.80-r2
2.80-r3
2.80-r4
2.80-r5
2.81-r0
Alpine:v3.13
dnsmasq
Package
- Name
- dnsmasq
- Purl
- pkg:apk/alpine/dnsmasq?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed2.83-r0
Affected versions
2.*
2.46-r0
2.47-r0
2.49-r0
2.50-r0
2.50-r1
2.51-r0
2.52-r0
2.52-r1
2.55-r0
2.57-r0
2.58-r0
2.59-r0
2.59-r1
2.60-r0
2.61-r0
2.62-r0
2.63-r0
2.64-r0
2.65-r0
2.66-r0
2.66-r1
2.66-r2
2.67-r0
2.68-r0
2.69-r0
2.70-r0
2.71-r0
2.72-r0
2.72-r1
2.73-r0
2.75-r0
2.75-r1
2.75-r2
2.76-r0
2.76-r1
2.76-r2
2.76-r3
2.76-r4
2.77-r0
2.78-r0
2.78-r1
2.78-r2
2.79-r0
2.79-r1
2.79-r2
2.80-r0
2.80-r1
2.80-r2
2.80-r3
2.80-r4
2.80-r5
2.81-r0
2.81-r1
2.82-r0
Alpine:v3.14
dnsmasq
Package
- Name
- dnsmasq
- Purl
- pkg:apk/alpine/dnsmasq?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed2.83-r0
Affected versions
2.*
2.46-r0
2.47-r0
2.49-r0
2.50-r0
2.50-r1
2.51-r0
2.52-r0
2.52-r1
2.55-r0
2.57-r0
2.58-r0
2.59-r0
2.59-r1
2.60-r0
2.61-r0
2.62-r0
2.63-r0
2.64-r0
2.65-r0
2.66-r0
2.66-r1
2.66-r2
2.67-r0
2.68-r0
2.69-r0
2.70-r0
2.71-r0
2.72-r0
2.72-r1
2.73-r0
2.75-r0
2.75-r1
2.75-r2
2.76-r0
2.76-r1
2.76-r2
2.76-r3
2.76-r4
2.77-r0
2.78-r0
2.78-r1
2.78-r2
2.79-r0
2.79-r1
2.79-r2
2.80-r0
2.80-r1
2.80-r2
2.80-r3
2.80-r4
2.80-r5
2.81-r0
2.81-r1
2.82-r0