CVE-2020-25686
LOW 3.7EPSS 4.9%
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.
- Affected
- dnsmasq
- CVSS v3.1 NVD
- 3.7 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N - CVSS v2.0 NVD
- 4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N - EPSS
- 4.87% chance of exploitation in the next 30 days, 92nd percentile
- Published
- 2021-01-20
- Updated
- 2025-11-04
Proof-of-concept exploits (1)
- knqyf263/dnspooq101★ · 2021-01-24
Exploit collections (1)
- DNSpooq PoC - dnsmasq cache poisoning (CVE-2020-25686, CVE-2020-25684, CVE-2020-25685).mdtzwlhack/Vulnerability
Security advisories
- 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-a…
- https://www.debian.org/security/2021/dsa-4844
- https://www.jsof-tech.com/disclosures/dnspooq
- https://www.kb.cert.org/vuls/id/434904