CVE-2019-6471

Description

A race condition leading to denial of service was found in the way bind handled certain malformed packets. A remote attacker who could cause the bind resolver to perform queries on a server, which responds deliberately with malformed answers, could cause named to exit.

Statement

This bind flaw can be exploited by a remote attacker (AV:N). However the attack works only if the attacker could cause the bind server to perform queries on another DNS server and the other DNS server deliberately responds with malformed answers (AC:H). No other special privileges are required by the attacker (PR:L). No user interaction is required from the server side (UI:N). The attacker can cause denial of service (A:H) by causing the named process to exit with an assertion flaw. There is no affect on the Confidentiality or Integrity of the system (C:N/I:N).

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.95.9N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityHighHighN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Acknowledgements

Red Hat would like to thank ISC for reporting this issue.

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