CVE-2020-25686 (GCVE-0-2020-25686)

Vulnerability from cvelistv5 – Published: 2021-01-20 16:47 – Updated: 2025-11-04 19:12
VLAI
Summary
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.
Severity
3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE
Assigner
redhat CNA under the redhat root
CNA scorecard B 82/100 over 1032 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
n/a dnsmasq Affected: dnsmasq 2.83
Show details on NVD website
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            "value": "Se encontr\u00f3 un fallo en dnsmasq versiones anteriores a 2.83.\u0026#xa0;Al recibir una consulta, dnsmasq no comprueba si existe una petici\u00f3n pendiente existente para el mismo nombre y reenv\u00eda una nueva petici\u00f3n.\u0026#xa0;Por defecto, se puede enviar un m\u00e1ximo de 150 consultas pendientes a los servidores aguas arriba, por lo que puede haber como m\u00e1ximo 150 consultas para el mismo nombre.\u0026#xa0;Este fallo permite a un atacante fuera de ruta en la red reduzca sustancialmente el n\u00famero de intentos que tendr\u00eda que realizar para falsificar una respuesta y hacer que dnsmasq la acepte.\u0026#xa0;Este problema se menciona en la secci\u00f3n \"Birthday Attacks\" de RFC5452.\u0026#xa0;Si se encadenaba con CVE-2020-25684, se reduce la complejidad del ataque de un ataque con \u00e9xito.\u0026#xa0;La mayor amenaza de esta vulnerabilidad es la integridad de los datos"
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  }
}



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