CVE-2019-6477

TCP-pipelined queries can bypass tcp-clients limit

HIGH
7.5
CVSS Score
Published: November 26, 2019 at 04:11 PM UTC
Updated: June 17, 2026 at 02:39 AM UTC
2 products affected across 2 vendorsFedoraBIND

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Severity
HIGH7.5
Exploit prediction
EPSS 4%

Description

With pipelining enabled each incoming query on a TCP connection requires a similar resource allocation to a query received via UDP or via TCP without pipelining enabled. A client using a TCP-pipelined connection to a server could consume more resources than the server has been provisioned to handle. When a TCP connection with a large number of pipelined queries is closed, the load on the server releasing these multiple resources can cause it to become unresponsive, even for queries that can be answered authoritatively or from cache. (This is most likely to be perceived as an intermittent server problem).

Affected

CVSS

7.5HIGHisc
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-400

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