CVE-2020-25686 Other in dnsmasq
An off-path attacker can reduce the effort required to forge DNS replies, compromising data integrity in dnsmasq.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-25686?
CVE-2020-25686 is a low-severity vulnerability in Debian Debian Linux, published on 20 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2020-25686?
It affects 4 products.
Products include Arista Eos, Debian Debian Linux, Fedoraproject Fedora, Thekelleys Dnsmasq.
How do I fix CVE-2020-25686?
Upgrade to a fixed version.
Is CVE-2020-25686 being exploited?
There is no known exploitation of CVE-2020-25686 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2020-25686, CLEANSTART-2026-AH64015, DEBIAN-CVE-2020-25686, GHSA-9xp3-mp9c-47rf, UBUNTU-CVE-2020-25686.