// For flags

CVE-2021-3448

dnsmasq: fixed outgoing port used when --server is used with an interface name

Severity Score

4.0
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity.

Se encontró un fallo en dnsmasq en versiones anteriores a 2.85. Cuando es configurado para usar un servidor específico para una interfaz de red determinada, dnsmasq usa un puerto fijado para enviar consultas. Un atacante en la red, capaz de encontrar el puerto de salida usado por dnsmasq, solo necesita adivinar la ID de transmisión aleatoria para falsificar una respuesta y lograr que dnsmasq la acepte. Este fallo hace que un ataque de envenenamiento de caché de DNS sea mucho más fácil. La mayor amenaza de esta vulnerabilidad es la integridad de los datos

A flaw was found in dnsmasq. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-03-16 CVE Reserved
  • 2021-04-08 CVE Published
  • 2023-12-23 EPSS Updated
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-358: Improperly Implemented Security Check for Standard
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Thekelleys
Search vendor "Thekelleys"
 Dnsmasq
Search vendor "Thekelleys" for product "Dnsmasq"
 < 2.85
Search vendor "Thekelleys" for product "Dnsmasq" and version " < 2.85"
-
Affected
Redhat
Search vendor "Redhat"
 Enterprise Linux
Search vendor "Redhat" for product "Enterprise Linux"
 8.0
Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 32
Search vendor "Fedoraproject" for product "Fedora" and version "32"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 34
Search vendor "Fedoraproject" for product "Fedora" and version "34"
-
Affected
Oracle
Search vendor "Oracle"
 Communications Cloud Native Core Network Function Cloud Native Environment
Search vendor "Oracle" for product "Communications Cloud Native Core Network Function Cloud Native Environment"
 1.9.0
Search vendor "Oracle" for product "Communications Cloud Native Core Network Function Cloud Native Environment" and version "1.9.0"
-
Affected