CVE-2018-5501 Explained : Impact and Mitigation

F5 Networks, Inc. disclosed a vulnerability affecting various versions of BIG-IP systems, leading to excessive buffering due to insufficient flow control in the TCP DNS profile.

Understanding CVE-2018-5501

This CVE involves a Denial of Service (DoS) risk on F5 BIG-IP systems, impacting the performance and stability of the affected versions.

What is CVE-2018-5501?

Excessive buffering may occur in certain scenarios on F5 BIG-IP systems running versions 13.0.0, 12.1.0 - 12.1.3.1, 11.6.x or 11.5.x, or 11.2.1, attributed to inadequate flow control in the TCP DNS profile.

The Impact of CVE-2018-5501

The vulnerability poses a risk of DoS attacks, potentially causing service disruptions and performance degradation on affected systems.

Technical Details of CVE-2018-5501

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The issue arises from the TCP DNS profile lacking sufficient flow control, leading to excessive buffering under specific conditions on the mentioned BIG-IP versions.

Affected Systems and Versions

Products: BIG-IP LTM, AAM, AFM, Analytics, APM, ASM, DNS, Edge Gateway, GTM, Link Controller, PEM, WebAccelerator, WebSafe
Versions: 13.0.0, 12.1.0 - 12.1.3.1, 11.6.1 - 11.6.x, 11.5.1 - 11.5.x, 11.2.1

Exploitation Mechanism

The vulnerability can be exploited by malicious actors to trigger DoS conditions by causing excessive buffering on the affected F5 BIG-IP systems.

Mitigation and Prevention

To address CVE-2018-5501, users should take immediate and long-term security measures.

Immediate Steps to Take

Apply vendor-supplied patches or updates promptly to mitigate the vulnerability.
Monitor network traffic for any signs of abnormal behavior that could indicate a DoS attack.

Long-Term Security Practices

Regularly update and patch F5 BIG-IP systems to prevent known vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

F5 Networks provides patches and updates to address the flow control issue in the TCP DNS profile on the affected versions of BIG-IP systems.