p PatchFirst

CVE-2020-25686

CVE-2020-25686

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 3.7 · Low · EPSS 5.5% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • dnsmasq

    Versions
    • dnsmasq 2.83: Affected

    No fix published

  • dnsmasq Debian:12

    Affected ranges
    • ECOSYSTEM: < 2.83-1

    Update to 2.83-1

  • dnsmasq Debian:13

    Affected ranges
    • ECOSYSTEM: < 2.83-1

    Update to 2.83-1

  • dnsmasq Debian:14

    Affected ranges
    • ECOSYSTEM: < 2.83-1

    Update to 2.83-1

  • dnsmasq Ubuntu:Pro:14.04:LTS

    Versions
    • 2.66-4ubuntu1
    • 2.67-1
    • 2.68-1
    • 2.68-1ubuntu0.1
    • 2.68-1ubuntu0.2
    • 2.68-1ubuntu0.2+esm1
    • 2.68-1ubuntu0.2+esm2
    • 2.68-1ubuntu0.2+esm3
    • 2.68-1ubuntu0.2+esm5
    • 2.68-1ubuntu0.2+esm6
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsmasq Ubuntu:16.04:LTS

    Versions
    • 2.75-1
    • 2.75-1ubuntu0.16.04.1
    • 2.75-1ubuntu0.16.04.2
    • 2.75-1ubuntu0.16.04.3
    • 2.75-1ubuntu0.16.04.4
    • 2.75-1ubuntu0.16.04.5
    Affected ranges
    • ECOSYSTEM: < 2.75-1ubuntu0.16.04.7

    Update to 2.75-1ubuntu0.16.04.7

  • dnsmasq Ubuntu:18.04:LTS

    Versions
    • 2.78-1
    • 2.78-3
    • 2.79-1
    Affected ranges
    • ECOSYSTEM: < 2.79-1ubuntu0.2

    Update to 2.79-1ubuntu0.2

  • dnsmasq Ubuntu:20.04:LTS

    Versions
    • 2.80-1ubuntu2
    • 2.80-1ubuntu4
    • 2.80-1.1ubuntu1
    Affected ranges
    • ECOSYSTEM: < 2.80-1.1ubuntu1.2

    Update to 2.80-1.1ubuntu1.2

Original sources

Check your server →