CVE-2019-6467
Description
A flaw was found in the way "nxdomain-redirect" feature was implemented in bind. An attacker could use this flaw on a server with a vulnerable configuration to cause bind to exit, denying service to other clients.
Statement
The most common bind configuration which is affected by this flaw is, if the server, in addition to performing NXDOMAIN redirection for recursive clients, is also serving a local copy of the root zone or using mirroring to provide the root zone, although other configurations are also possible.
Mitigation
Exploitation of this defect can be effectively prevented by disabling the nxdomain-redirect feature in the nameserver's configuration.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/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:L/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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