CVE-2018-5743 : Security Advisory and Response

BIND is designed to limit the number of TCP clients that can connect simultaneously. However, a flaw in the code allowed attackers to exceed this limit, impacting various versions of BIND.

Understanding CVE-2018-5743

This CVE involves a vulnerability in BIND that could be exploited to bypass the intended limit on simultaneous TCP connections.

What is CVE-2018-5743?

BIND, a DNS server software, had a flaw in its code that failed to effectively restrict the number of simultaneous TCP connections, potentially leading to resource exhaustion.

The Impact of CVE-2018-5743

The vulnerability could allow attackers to exhaust the pool of file descriptors available to named, affecting network connections and file management.

Technical Details of CVE-2018-5743

BIND versions 9.9.0 to 9.10.8-P1, 9.11.0 to 9.11.6, 9.12.0 to 9.12.4, and 9.14.0 were affected, along with specific versions of the BIND Supported Preview Edition and the 9.13 development branch.

Vulnerability Description

The flaw in BIND's code allowed attackers to surpass the intended limit on simultaneous TCP connections, potentially causing resource exhaustion.

Affected Systems and Versions

BIND 9.9.0 to 9.10.8-P1, 9.11.0 to 9.11.6, 9.12.0 to 9.12.4, 9.14.0
BIND Supported Preview Edition versions 9.9.3-S1 to 9.11.5-S3, 9.11.5-S5
Versions 9.13.0 to 9.13.7 of the 9.13 development branch

Exploitation Mechanism

Attackers could exploit the vulnerability to exhaust file descriptors available to named, affecting network connections and file management.

Mitigation and Prevention

To address CVE-2018-5743, users should take immediate steps and implement long-term security practices.

Immediate Steps to Take

Upgrade to fixed versions: BIND 9.11.6-P1, 9.12.4-P1, 9.14.1

Long-Term Security Practices

Regularly update BIND to the latest secure versions
Monitor network traffic for unusual patterns

Patching and Updates

Upgrade to the recommended versions to mitigate the vulnerability