CVE-2019-6467 : Vulnerability Insights and Analysis

CVE-2019-6467 is a vulnerability in BIND 9 that can lead to an assertion failure due to a programming error in the nxdomain-redirect feature. This issue affects versions 9.12.0 to 9.12.4, 9.14.0, and all releases in the 9.13 development branch.

Understanding CVE-2019-6467

This CVE involves a specific error in the nxdomain-redirect feature of BIND 9 that can trigger an assertion failure in query.c, potentially impacting the server's functionality.

What is CVE-2019-6467?

The nxdomain-redirect feature in BIND 9 may result in an assertion failure in query.c due to a programming error. This can occur when the alternate namespace used by nxdomain-redirect is a descendant of a locally served zone, affecting server configurations.

The Impact of CVE-2019-6467

An attacker exploiting this vulnerability can cause BIND to exit, denying service to other clients. The affected versions include BIND 9.12.0 to 9.12.4, 9.14.0, and all releases in the 9.13 development branch.

Technical Details of CVE-2019-6467

This section provides detailed technical information about the vulnerability.

Vulnerability Description

A programming error in the nxdomain-redirect feature can lead to an assertion failure in query.c, affecting servers with vulnerable configurations.

Affected Systems and Versions

Product: BIND 9
Vendor: ISC
Versions: BIND 9.12.0 to 9.12.4, 9.14.0, and all releases in the 9.13 development branch

Exploitation Mechanism

The vulnerability can be triggered by deliberately exploiting the condition on a server with a vulnerable configuration, causing BIND to exit and deny service to clients.

Mitigation and Prevention

Protecting systems from CVE-2019-6467 involves immediate steps and long-term security practices.

Immediate Steps to Take

Disable the nxdomain-redirect feature in the nameserver's configuration to prevent exploitation of the defect.

Long-Term Security Practices

Regularly update BIND to the patched releases closest to the current version.

Patching and Updates

Upgrade to the patched releases most closely related to your current version of BIND:

BIND 9.12.4-P1
BIND 9.14.1