CVE-2020-25684
A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
- CVSS v3.1
- 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
- 4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N - EPSS
- 4.04% chance of exploitation in the next 30 days, 90th percentile
- Published
- 2021-01-20
- Updated
- 2025-11-04
Proof-of-concept exploits (1)
- knqyf263/dnspooq101★ · 2021-01-24