CVE-2020-25686

LowCVSS 3.7/10Last modified Jun 17, 2026

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.

Metrics

CVSS 3.1 3.7/10CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness enumeration

CWE-358CWE-290

Affected software

VendorProductVersions
n/adnsmasqdnsmasq 2.83

References

Timeline

Published
Jan 20, 2021
Last modified
Jun 17, 2026
NVD status
Modified

Related CVEs from 2020

CVE-2020-256875.9A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before itCVE-2020-256883.5A flaw was found in rhacm versions before 2.0.5 and before 2.1.0. Two internal service APIs were incorrectly provisioned using a test certifCVE-2020-256896.5A memory leak flaw was found in WildFly in all versions up to 21.0.0.Final, where host-controller tries to reconnect in a loop, generating nCVE-2020-25693.9Vulnerability in the Oracle Applications DBA component of Oracle Database Server. Supported versions that are affected are 11.2.0.4, 12.1.0.CVE-2020-256908.8An out-of-bounds write flaw was found in FontForge in versions before 20200314 while parsing SFD files containing certain LayerCount tokens.CVE-2020-256917.5A flaw was found in darkhttpd. Invalid error handling allows remote attackers to cause denial-of-service by accessing a file with a large moCVE-2020-256927.5A NULL pointer dereference was found in OpenLDAP server and was fixed in openldap 2.4.55, during a request for renaming RDNs. An unauthenticCVE-2020-256938.1A flaw was found in CImg in versions prior to 2.9.3. Integer overflows leading to heap buffer overflows in load_pnm() can be triggered by a CVE-2020-256948.1A flaw was found in PostgreSQL versions before 13.1, before 12.5, before 11.10, before 10.15, before 9.6.20 and before 9.5.24. If a client aCVE-2020-256958.8A flaw was found in PostgreSQL versions before 13.1, before 12.5, before 11.10, before 10.15, before 9.6.20 and before 9.5.24. An attacker hCVE-2020-256967.5A flaw was found in the psql interactive terminal of PostgreSQL in versions before 13.1, before 12.5, before 11.10, before 10.15, before 9.6CVE-2020-256977.0A privilege escalation flaw was found in the Xorg-x11-server due to a lack of authentication for X11 clients. This flaw allows an attacker t
CVE-2020-25686: Low severity, CVSS 3.7 | Vulnix