Low severity · published Jan 20, 2021
CVE-2020-25686
A flaw was found in dnsmasq before version 2.83
3.7
CVSS
5.5%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)5.5% · higher than 93% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
10.0 · source: NVD
DN
Dnsmasq · Thekelleys
before 2.83 · source: NVD
EO
Eos · Arista
4.21 before 4.21.14m; 4.22 before 4.22.9m; 4.23 before 4.23.7m; 4.24 before 4.24.5m; 4.25 before 4.25.2f · source: NVD
FE
Fedora · Fedoraproject
32; 33 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-25686
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-25686
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=1890125
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
Third Party Advisory
https://security.gentoo.org/glsa/202101-17
Third Party Advisory
https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61
Third Party Advisory
https://www.debian.org/security/2021/dsa-4844
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